1
|
Arceneaux JS, Brockman AA, Khurana R, Chalkley MBL, Geben LC, Krbanjevic A, Vestal M, Zafar M, Weatherspoon S, Mobley BC, Ess KC, Ihrie RA. Multiparameter quantitative analyses of diagnostic cells in brain tissues from tuberous sclerosis complex. CYTOMETRY. PART B, CLINICAL CYTOMETRY 2024. [PMID: 38953209 DOI: 10.1002/cyto.b.22194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 06/05/2024] [Accepted: 06/11/2024] [Indexed: 07/03/2024]
Abstract
The advent of high-dimensional imaging offers new opportunities to molecularly characterize diagnostic cells in disorders that have previously relied on histopathological definitions. One example case is found in tuberous sclerosis complex (TSC), a developmental disorder characterized by systemic growth of benign tumors. Within resected brain tissues from patients with TSC, detection of abnormally enlarged balloon cells (BCs) is pathognomonic for this disorder. Though BCs can be identified by an expert neuropathologist, little is known about the specificity and broad applicability of protein markers for these cells, complicating classification of proposed BCs identified in experimental models of this disorder. Here, we report the development of a customized machine learning pipeline (BAlloon IDENtifier; BAIDEN) that was trained to prospectively identify BCs in tissue sections using a histological stain compatible with high-dimensional cytometry. This approach was coupled to a custom 36-antibody panel and imaging mass cytometry (IMC) to explore the expression of multiple previously proposed BC marker proteins and develop a descriptor of BC features conserved across multiple tissue samples from patients with TSC. Here, we present a modular workflow encompassing BAIDEN, a custom antibody panel, a control sample microarray, and analysis pipelines-both open-source and in-house-and apply this workflow to understand the abundance, structure, and signaling activity of BCs as an example case of how high-dimensional imaging can be applied within human tissues.
Collapse
Affiliation(s)
- Jerome S Arceneaux
- Department of Biochemistry, Cancer Biology, Neuroscience, and Pharmacology, Meharry Medical College, Nashville, Tennessee, USA
| | - Asa A Brockman
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Rohit Khurana
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Mary-Bronwen L Chalkley
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Laura C Geben
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
| | - Aleksandar Krbanjevic
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Matthew Vestal
- Duke University Children's Hospital and Health Center, Durham, North Carolina, USA
| | - Muhammad Zafar
- Duke University Children's Hospital and Health Center, Durham, North Carolina, USA
| | - Sarah Weatherspoon
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee, USA
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Bret C Mobley
- Department of Pathology, Microbiology, & Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Kevin C Ess
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Section of Child Neurology, University of Colorado Anschutz Medical Center, Aurora, Colorado, USA
| | - Rebecca A Ihrie
- Department of Cell & Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| |
Collapse
|
2
|
Ribierre T, Bacq A, Donneger F, Doladilhe M, Maletic M, Roussel D, Le Roux I, Chassoux F, Devaux B, Adle-Biassette H, Ferrand-Sorbets S, Dorfmüller G, Chipaux M, Baldassari S, Poncer JC, Baulac S. Targeting pathological cells with senolytic drugs reduces seizures in neurodevelopmental mTOR-related epilepsy. Nat Neurosci 2024; 27:1125-1136. [PMID: 38710875 PMCID: PMC11156583 DOI: 10.1038/s41593-024-01634-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 03/28/2024] [Indexed: 05/08/2024]
Abstract
Cortical malformations such as focal cortical dysplasia type II (FCDII) are associated with pediatric drug-resistant epilepsy that necessitates neurosurgery. FCDII results from somatic mosaicism due to post-zygotic mutations in genes of the PI3K-AKT-mTOR pathway, which produce a subset of dysmorphic cells clustered within healthy brain tissue. Here we show a correlation between epileptiform activity in acute cortical slices obtained from human surgical FCDII brain tissues and the density of dysmorphic neurons. We uncovered multiple signatures of cellular senescence in these pathological cells, including p53/p16 expression, SASP expression and senescence-associated β-galactosidase activity. We also show that administration of senolytic drugs (dasatinib/quercetin) decreases the load of senescent cells and reduces seizure frequency in an MtorS2215F FCDII preclinical mouse model, providing proof of concept that senotherapy may be a useful approach to control seizures. These findings pave the way for therapeutic strategies selectively targeting mutated senescent cells in FCDII brain tissue.
Collapse
Affiliation(s)
- Théo Ribierre
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
- NeuroNA Human Cellular Neuroscience Platform, Fondation Campus Biotech Geneva, Geneva, Switzerland
| | - Alexandre Bacq
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Florian Donneger
- Institut du Fer à Moulin, INSERM, Sorbonne Université, UMR-S 1270, Paris, France
| | - Marion Doladilhe
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Marina Maletic
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Delphine Roussel
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Isabelle Le Roux
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Francine Chassoux
- Service de Neurochirurgie, AP-HP, Hôpital Lariboisière, Paris, France
- GHU Paris, Psychiatrie et Neurosciences, Paris, France
| | - Bertrand Devaux
- Service de Neurochirurgie, AP-HP, Hôpital Lariboisière, Paris, France
- GHU Paris, Psychiatrie et Neurosciences, Paris, France
| | - Homa Adle-Biassette
- Université de Paris Cité, Service d'Anatomie Pathologique, AP-HP, Hôpital Lariboisière, DMU DREAM, UMR 1141, INSERM, Paris, France
| | | | - Georg Dorfmüller
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital, Paris, France
| | - Mathilde Chipaux
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital, Paris, France
| | - Sara Baldassari
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France
| | | | - Stéphanie Baulac
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié Salpêtrière, Paris, France.
| |
Collapse
|
3
|
Lee AT, Chang EF, Paredes MF, Nowakowski TJ. Large-scale neurophysiology and single-cell profiling in human neuroscience. Nature 2024; 630:587-595. [PMID: 38898291 DOI: 10.1038/s41586-024-07405-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 04/09/2024] [Indexed: 06/21/2024]
Abstract
Advances in large-scale single-unit human neurophysiology, single-cell RNA sequencing, spatial transcriptomics and long-term ex vivo tissue culture of surgically resected human brain tissue have provided an unprecedented opportunity to study human neuroscience. In this Perspective, we describe the development of these paradigms, including Neuropixels and recent brain-cell atlas efforts, and discuss how their convergence will further investigations into the cellular underpinnings of network-level activity in the human brain. Specifically, we introduce a workflow in which functionally mapped samples of human brain tissue resected during awake brain surgery can be cultured ex vivo for multi-modal cellular and functional profiling. We then explore how advances in human neuroscience will affect clinical practice, and conclude by discussing societal and ethical implications to consider. Potential findings from the field of human neuroscience will be vast, ranging from insights into human neurodiversity and evolution to providing cell-type-specific access to study and manipulate diseased circuits in pathology. This Perspective aims to provide a unifying framework for the field of human neuroscience as we welcome an exciting era for understanding the functional cytoarchitecture of the human brain.
Collapse
Affiliation(s)
- Anthony T Lee
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Edward F Chang
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Mercedes F Paredes
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Tomasz J Nowakowski
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA.
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA.
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, USA.
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA, USA.
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA.
| |
Collapse
|
4
|
Gooley S, Perucca P, Tubb C, Hildebrand MS, Berkovic SF. Somatic mosaicism in focal epilepsies. Curr Opin Neurol 2024; 37:105-114. [PMID: 38235675 DOI: 10.1097/wco.0000000000001244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
PURPOSE OF REVIEW Over the past decade, it has become clear that brain somatic mosaicism is an important contributor to many focal epilepsies. The number of cases and the range of underlying pathologies with somatic mosaicism are rapidly increasing. This growth in somatic variant discovery is revealing dysfunction in distinct molecular pathways in different focal epilepsies. RECENT FINDINGS We briefly summarize the current diagnostic yield of pathogenic somatic variants across all types of focal epilepsy where somatic mosaicism has been implicated and outline the specific molecular pathways affected by these variants. We will highlight the recent findings that have increased diagnostic yields such as the discovery of pathogenic somatic variants in novel genes, and new techniques that allow the discovery of somatic variants at much lower variant allele fractions. SUMMARY A major focus will be on the emerging evidence that somatic mosaicism may contribute to some of the more common focal epilepsies such as temporal lobe epilepsy with hippocampal sclerosis, which could lead to it being re-conceptualized as a genetic disorder.
Collapse
Affiliation(s)
- Samuel Gooley
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg
| | - Piero Perucca
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg
- Department of Neuroscience, Central Clinical School, Monash University
- Department of Neurology, Alfred Health, Melbourne
- Department of Neurology, The Royal Melbourne Hospital
| | - Caitlin Tubb
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Neuroscience Group, Murdoch Children's Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Heidelberg
| |
Collapse
|
5
|
Ferri L, Menghi V, Licchetta L, Dimartino P, Minardi R, Davì C, Di Vito L, Cifaldi E, Zenesini C, Gozzo F, Pelliccia V, Mariani V, de Spelorzi YCC, Gustincich S, Seri M, Tassi L, Pippucci T, Bisulli F. Detection of somatic and germline pathogenic variants in adult cohort of drug-resistant focal epilepsies. Epilepsy Behav 2024; 153:109716. [PMID: 38508103 DOI: 10.1016/j.yebeh.2024.109716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024]
Abstract
OBJECTIVE This study investigates the prevalence of pathogenic variants in the mechanistic target of rapamycin (mTOR) pathway in surgical specimens of malformations of cortical development (MCDs) and cases with negative histology. The study also aims to evaluate the predictive value of genotype-histotype findings on the surgical outcome. METHODS The study included patients with drug-resistant focal epilepsy who underwent epilepsy surgery. Cases were selected based on histopathological diagnosis, focusing on MCDs and negative findings. We included brain tissues both as formalin-fixed, paraffin-embedded (FFPE) or fresh frozen (FF) samples. Single-molecule molecular inversion probes (smMIPs) analysis was conducted, targeting the MTOR gene in FFPE samples and 10 genes within the mTOR pathway in FF samples. Correlations between genotype-histotype and surgical outcome were examined. RESULTS We included 78 patients for whom we obtained 28 FFPE samples and 50 FF tissues. Seventeen pathogenic variants (22 %) were identified and validated, with 13 being somatic within the MTOR gene and 4 germlines (2 DEPDC5, 1 TSC1, 1 TSC2). Pathogenic variants in mTOR pathway genes were exclusively found in FCDII and TSC cases, with a significant association between FCD type IIb and MTOR genotype (P = 0.003). Patients carrying mutations had a slightly better surgical outcome than the overall cohort, however it results not significant. The FCDII diagnosed cases more frequently had normal neuropsychological test, a higher incidence of auras, fewer multiple seizure types, lower occurrence of seizures with awareness impairment, less ictal automatisms, fewer Stereo-EEG investigations, and a longer period long-life of seizure freedom before surgery. SIGNIFICANCE This study confirms that somatic MTOR variants represent the primary genetic alteration detected in brain specimens from FCDII/TSC cases, while germline DEPDC5, TSC1/TSC2 variants are relatively rare. Systematic screening for these mutations in surgically treated patients' brain specimens can aid histopathological diagnoses and serve as a biomarker for positive surgical outcomes. Certain clinical features associated with pathogenic variants in mTOR pathway genes may suggest a genetic etiology in FCDII patients.
Collapse
Affiliation(s)
- L Ferri
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (full member of the European Reference Network EpiCARE), Via Altura 3, Bologna 40139, Italy; Department of Biomedical and NeuroMotor Sciences, University of Bologna, Via Massarenti, 9 - Pad. 11 - 40138 Bologna, Italy
| | - V Menghi
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Via Massarenti, 9 - Pad. 11 - 40138 Bologna, Italy; Neurology Unit, Rimini "Infermi" Hospital-AUSL Romagna, Rimini, Italy
| | - L Licchetta
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (full member of the European Reference Network EpiCARE), Via Altura 3, Bologna 40139, Italy
| | - P Dimartino
- Department of Medical and Surgical Sciences, University of Bologna, Via Massarenti, 9 - Pad. 11 - 40138 Bologna, Italy
| | - R Minardi
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (full member of the European Reference Network EpiCARE), Via Altura 3, Bologna 40139, Italy
| | - C Davì
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (full member of the European Reference Network EpiCARE), Via Altura 3, Bologna 40139, Italy
| | - L Di Vito
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (full member of the European Reference Network EpiCARE), Via Altura 3, Bologna 40139, Italy
| | - E Cifaldi
- IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | - C Zenesini
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (full member of the European Reference Network EpiCARE), Via Altura 3, Bologna 40139, Italy
| | - F Gozzo
- Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milano, Italy
| | - V Pelliccia
- Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milano, Italy
| | - V Mariani
- Neurology and Stroke Unit, ASST Santi Paolo e Carlo, Presidio San Carlo Borromeo, Milano, Italy
| | - Y C C de Spelorzi
- Genomics Facility, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - S Gustincich
- Center for Human Technologies, Non-coding RNAs and RNA-based Therapeutics, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - M Seri
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Via Massarenti, 9 - Pad. 11 - 40138 Bologna, Italy; IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - L Tassi
- Claudio Munari Epilepsy Surgery Center, Niguarda Hospital, Milano, Italy
| | - T Pippucci
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Via Massarenti, 9 - Pad. 11 - 40138 Bologna, Italy; IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - F Bisulli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (full member of the European Reference Network EpiCARE), Via Altura 3, Bologna 40139, Italy; Department of Biomedical and NeuroMotor Sciences, University of Bologna, Via Massarenti, 9 - Pad. 11 - 40138 Bologna, Italy.
| |
Collapse
|
6
|
Kovačević M, Sokić D, Ristić A, Berisavac I, Ercegovac M, Milićević O, Vojvodić N. Familial occurrence of seizure disorders across MRI defined structural focal epilepsy etiology. J Clin Neurosci 2024; 123:15-22. [PMID: 38508018 DOI: 10.1016/j.jocn.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 03/10/2024] [Accepted: 03/13/2024] [Indexed: 03/22/2024]
Abstract
BACKGROUND Previous studies have established familial occurrence of epilepsy and seizure disorders and early age of epilepsy onset as predictors of genetic epilepsy, but have not evaluated the rate of their occurrence in patients with different epilepsy etiology. Our study determines the distribution of familial occurrence and age of epilepsy onset across structural focal epilepsy (FE) etiology in a large FE cohort. METHODS Records of 1354 consecutive patients evaluated for epilepsy and seizure disorders in The Neurology Clinic, University Clinical Center of Serbia from 2008 to 2019 were screened for FE. Structural etiology, lobar diagnosis, familial occurrence, and age at epilepsy onset were determined. Patients with a. nonlesional focal epilepsy (NLFE), b. hippocampal sclerosis (HS) and c. congenital or perinatal etiology (CPE) were classified as NAFE, while patients with an identified acquired focal epilepsy (AFE) constituted the control group. RESULTS We identified 965 patients with FE, 329 (34.1 %) with NLFE, 213 (22.1 %) with HS, 174 (18.0 %) with CPE and 249 (25.8 %) with AFE. Familial occurrence was identified in 160 (16.6 %), 19.1 % of patients with NAFE and 9.2 % of AFE (p = 0.003). Patients with NAFE had a younger age of epilepsy onset (13 vs. 18 years, p < 0.001). The highest proportion of familial occurrence was found in patients with NLFE (23.7 %), while the youngest median age of epilepsy onset was identified in patients with HS (12 years) and CPE (11 years). CONCLUSION Patients with NAFE frequently have familial occurrence of epilepsy and have an earlier age of epilepsy onset than patients with AFE.
Collapse
Affiliation(s)
- Maša Kovačević
- Neurology Clinic, University Clinical Center of Serbia, University of Belgrade Faculty of Medicine, Serbia; Faculty of Medicine, University of Belgrade, Serbia.
| | - Dragoslav Sokić
- Neurology Clinic, University Clinical Center of Serbia, University of Belgrade Faculty of Medicine, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| | - Aleksandar Ristić
- Neurology Clinic, University Clinical Center of Serbia, University of Belgrade Faculty of Medicine, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| | - Ivana Berisavac
- Neurology Clinic, University Clinical Center of Serbia, University of Belgrade Faculty of Medicine, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| | - Marko Ercegovac
- Neurology Clinic, University Clinical Center of Serbia, University of Belgrade Faculty of Medicine, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| | | | - Nikola Vojvodić
- Neurology Clinic, University Clinical Center of Serbia, University of Belgrade Faculty of Medicine, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| |
Collapse
|
7
|
Man A, Di Scipio M, Grewal S, Suk Y, Trinari E, Ejaz R, Whitney R. The Genetics of Tuberous Sclerosis Complex and Related mTORopathies: Current Understanding and Future Directions. Genes (Basel) 2024; 15:332. [PMID: 38540392 PMCID: PMC10970281 DOI: 10.3390/genes15030332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 03/02/2024] [Accepted: 03/02/2024] [Indexed: 06/14/2024] Open
Abstract
The mechanistic target of rapamycin (mTOR) pathway serves as a master regulator of cell growth, proliferation, and survival. Upregulation of the mTOR pathway has been shown to cause malformations of cortical development, medically refractory epilepsies, and neurodevelopmental disorders, collectively described as mTORopathies. Tuberous sclerosis complex (TSC) serves as the prototypical mTORopathy. Characterized by the development of benign tumors in multiple organs, pathogenic variants in TSC1 or TSC2 disrupt the TSC protein complex, a negative regulator of the mTOR pathway. Variants in critical domains of the TSC complex, especially in the catalytic TSC2 subunit, correlate with increased disease severity. Variants in less crucial exons and non-coding regions, as well as those undetectable with conventional testing, may lead to milder phenotypes. Despite the assumption of complete penetrance, expressivity varies within families, and certain variants delay disease onset with milder neurological effects. Understanding these genotype-phenotype correlations is crucial for effective clinical management. Notably, 15% of patients have no mutation identified by conventional genetic testing, with the majority of cases postulated to be caused by somatic TSC1/TSC2 variants which present complex diagnostic challenges. Advancements in genetic testing, prenatal screening, and precision medicine hold promise for changing the diagnostic and treatment paradigm for TSC and related mTORopathies. Herein, we explore the genetic and molecular mechanisms of TSC and other mTORopathies, emphasizing contemporary genetic methods in understanding and diagnosing the condition.
Collapse
Affiliation(s)
- Alice Man
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Matteo Di Scipio
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Shan Grewal
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Yujin Suk
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Elisabetta Trinari
- Division of Developmental Pediatrics, Department of Pediatrics, McMaster Children’s Hospital, Hamilton, ON L8N 3Z5, Canada
| | - Resham Ejaz
- Division of Genetics, Department of Pediatrics, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Robyn Whitney
- Division of Neurology, Department of Pediatrics, McMaster University, Hamilton, ON L8S 4L8, Canada
| |
Collapse
|
8
|
Nguyen LH, Xu Y, Nair M, Bordey A. The mTOR pathway genes MTOR, Rheb, Depdc5, Pten, and Tsc1 have convergent and divergent impacts on cortical neuron development and function. eLife 2024; 12:RP91010. [PMID: 38411613 PMCID: PMC10942629 DOI: 10.7554/elife.91010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Abstract
Brain somatic mutations in various components of the mTOR complex 1 (mTORC1) pathway have emerged as major causes of focal malformations of cortical development and intractable epilepsy. While these distinct gene mutations converge on excessive mTORC1 signaling and lead to common clinical manifestations, it remains unclear whether they cause similar cellular and synaptic disruptions underlying cortical network hyperexcitability. Here, we show that in utero activation of the mTORC1 activator genes, Rheb or MTOR, or biallelic inactivation of the mTORC1 repressor genes, Depdc5, Tsc1, or Pten in the mouse medial prefrontal cortex leads to shared alterations in pyramidal neuron morphology, positioning, and membrane excitability but different changes in excitatory synaptic transmission. Our findings suggest that, despite converging on mTORC1 signaling, mutations in different mTORC1 pathway genes differentially impact cortical excitatory synaptic activity, which may confer gene-specific mechanisms of hyperexcitability and responses to therapeutic intervention.
Collapse
Affiliation(s)
- Lena H Nguyen
- Department of Neuroscience, School of Behavioral and Brain Sciences, University of Texas at DallasRichardsonUnited States
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of MedicineNew HavenUnited States
| | - Youfen Xu
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of MedicineNew HavenUnited States
| | - Maanasi Nair
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of MedicineNew HavenUnited States
| | - Angelique Bordey
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of MedicineNew HavenUnited States
| |
Collapse
|
9
|
Muller M, Bélanger J, Hadj-Aissa I, Zhang C, Sephton CF, Dutchak PA. GATOR1 Mutations Impair PI3 Kinase-Dependent Growth Factor Signaling Regulation of mTORC1. Int J Mol Sci 2024; 25:2068. [PMID: 38396745 PMCID: PMC10889792 DOI: 10.3390/ijms25042068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
GATOR1 (GAP Activity TOward Rag 1) is an evolutionarily conserved GTPase-activating protein complex that controls the activity of mTORC1 (mammalian Target Of Rapamycin Complex 1) in response to amino acid availability in cells. Genetic mutations in the GATOR1 subunits, NPRL2 (nitrogen permease regulator-like 2), NPRL3 (nitrogen permease regulator-like 3), and DEPDC5 (DEP domain containing 5), have been associated with epilepsy in humans; however, the specific effects of these mutations on GATOR1 function and mTORC1 regulation are not well understood. Herein, we report that epilepsy-linked mutations in the NPRL2 subunit of GATOR1, NPRL2-L105P, -T110S, and -D214H, increase basal mTORC1 signal transduction in cells. Notably, we show that NPRL2-L105P is a loss-of-function mutation that disrupts protein interactions with NPRL3 and DEPDC5, impairing GATOR1 complex assembly and resulting in high mTORC1 activity even under conditions of amino acid deprivation. Furthermore, our studies reveal that the GATOR1 complex is necessary for the rapid and robust inhibition of mTORC1 in response to growth factor withdrawal or pharmacological inhibition of phosphatidylinositol-3 kinase (PI3K). In the absence of the GATOR1 complex, cells are refractory to PI3K-dependent inhibition of mTORC1, permitting sustained translation and restricting the nuclear localization of TFEB, a transcription factor regulated by mTORC1. Collectively, our results show that epilepsy-linked mutations in NPRL2 can block GATOR1 complex assembly and restrict the appropriate regulation of mTORC1 by canonical PI3K-dependent growth factor signaling in the presence or absence of amino acids.
Collapse
Affiliation(s)
| | | | | | | | | | - Paul A. Dutchak
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, QC G1J 2G3, Canada
| |
Collapse
|
10
|
Yang D, Wang J, Qin Z, Feng J, Mao C, Chen Y, Huang X, Ruan Y. Phenotypic and genotypic characterization of NPRL3-related epilepsy: Two case reports and literature review. Epilepsia Open 2024; 9:33-40. [PMID: 37902097 PMCID: PMC10839296 DOI: 10.1002/epi4.12856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/20/2023] [Indexed: 10/31/2023] Open
Abstract
Nitrogen permease regulator-like 3 (NPRL3) has been reported to play a role in seizure onset. The principal manifestation of NPRL3-related epilepsy is a range of epilepsy-associated syndromes, such as familial focal epilepsy with variable foci (FFEVF), sleep-related hypermotor epilepsy (SHE), and temporal lobe epilepsy (TLE). The association between phenotype and genotype of NPRL3 mutations remains inadequately described. This study aimed to explore the phenotypic and genotypic spectra of NPRL3-related epilepsy. We reported two novel NPRL3 variants in two unrelated epilepsy cases, including a nonsense (c.1174C > T, p.Gln392*) and a missense variant (c.1322C > T, p.Thr441Met). Following a review of the literature, a total of 116 cases of NPRL3-related epilepsy were assessed, mostly with nonsense and frameshift mutations. Our findings suggest that patients harboring various NPRL3 variants exhibit variable clinical manifestations. In addition, it may be worthwhile to consider theexistence of NPRL3 mutations in epilepsy patients with a family history. This study provides useful information for the treatment and prognosis by expanding the phenotypic and genotypic spectrum of NPRL3-related epilepsy. PLAIN LANGUAGE SUMMARY: This study expands the phenotypic and genotypic spectra of NPRL3-related epilepsy by reporting two cases with different novel variants. Following a review of the literature, it was observed that patients harboring various NPRL3 variants exhibited a variability of clinical manifestations. Also, patients carrying nonsense mutations are frequently prone to drug resistance and other severe comorbidities such as developmental delay, but more cases need to be collected to confirm these findings.
Collapse
Affiliation(s)
- Dongling Yang
- Ruikang Clinical Medical CollegeGuangxi University of Chinese MedicineNanningChina
- Department of Pediatric Neurology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionGuangxi Clinical Research Center for Pediatric DiseasesNanningChina
| | - Jinqiu Wang
- Department of Pediatric Neurology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionGuangxi Clinical Research Center for Pediatric DiseasesNanningChina
| | - Zailong Qin
- Guangxi Key Laboratory of Precision Medicine for Genetic DiseasesMaternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionNanningChina
- Genetic and Metabolic Central LaboratoryGuangxi Birth Defects Research and Prevention InstituteNanningChina
| | - Juntan Feng
- Department of Pediatric Neurology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionGuangxi Clinical Research Center for Pediatric DiseasesNanningChina
| | - Chengyun Mao
- Department of Pediatric Neurology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionGuangxi Clinical Research Center for Pediatric DiseasesNanningChina
| | - Yuyi Chen
- Department of Pediatric Neurology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionGuangxi Clinical Research Center for Pediatric DiseasesNanningChina
| | - Xuelin Huang
- Department of Pediatric Neurology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionGuangxi Clinical Research Center for Pediatric DiseasesNanningChina
| | - Yiyan Ruan
- Department of Pediatric Neurology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionGuangxi Clinical Research Center for Pediatric DiseasesNanningChina
- Guangxi Key Laboratory of Precision Medicine for Genetic DiseasesMaternal and Child Health Hospital of Guangxi Zhuang Autonomous RegionNanningChina
| |
Collapse
|
11
|
Nguyen LH, Xu Y, Nair M, Bordey A. The mTOR pathway genes mTOR, Rheb, Depdc5, Pten, and Tsc1 have convergent and divergent impacts on cortical neuron development and function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.11.553034. [PMID: 37609221 PMCID: PMC10441381 DOI: 10.1101/2023.08.11.553034] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Brain somatic mutations in various components of the mTOR complex 1 (mTORC1) pathway have emerged as major causes of focal malformations of cortical development and intractable epilepsy. While these distinct gene mutations converge on excessive mTORC1 signaling and lead to common clinical manifestations, it remains unclear whether they cause similar cellular and synaptic disruptions underlying cortical network hyperexcitability. Here, we show that in utero activation of the mTORC1 activators, Rheb or mTOR, or biallelic inactivation of the mTORC1 repressors, Depdc5, Tsc1, or Pten in mouse medial prefrontal cortex leads to shared alterations in pyramidal neuron morphology, positioning, and membrane excitability but different changes in excitatory synaptic transmission. Our findings suggest that, despite converging on mTORC1 signaling, mutations in different mTORC1 pathway genes differentially impact cortical excitatory synaptic activity, which may confer gene-specific mechanisms of hyperexcitability and responses to therapeutic intervention.
Collapse
Affiliation(s)
- Lena H. Nguyen
- Department Neuroscience, School of Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX 75080, USA
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Youfen Xu
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Maanasi Nair
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Angelique Bordey
- Departments of Neurosurgery and Cellular & Molecular Physiology, Wu Tsai Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| |
Collapse
|
12
|
Blümcke I. Neuropathology and epilepsy surgery - 2024 update. FREE NEUROPATHOLOGY 2024; 5:5-8. [PMID: 38532826 PMCID: PMC10964794 DOI: 10.17879/freeneuropathology-2024-5347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/11/2024] [Indexed: 03/28/2024]
Abstract
Neuropathology-based studies in neurosurgically resected brain tissue obtained from carefully examined patients with focal epilepsies remain a treasure box for excellent insights into human neuroscience, including avenues to better understand the neurobiology of human brain organization and neuronal hyperexcitability at the cellular level including glio-neuronal interaction. It also allows to translate results from animal models in order to develop personalized treatment strategies in the near future. A nice example of this is the discovery of a new disease entity in 2017, termed mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy or MOGHE, in the frontal lobe of young children with intractable seizures. In 2021, a brain somatic missense mutation of the galactose transporter SLC35A2 leading to altered glycosylation of lipoproteins in the Golgi apparatus was detected in 50 % of MOGHE samples. In 2023, the first clinical trial evaluated galactose supplementation in patients with histopathologically confirmed MOGHE carrying brain somatic SLC35A2 mutations that were not seizure free after surgery. The promising results of this pilot trial are an example of personalized medicine in the arena of epileptology. Besides this, neuropathological studies of epilepsy samples have revealed many other fascinating results for the main disease categories in focal epilepsies, such as the first deep-learning based classifier for Focal Cortical Dysplasia, or the genomic landscape of cortical malformations showing new candidate genes such as PTPN11, which is associated with ganglioglioma and adverse clinical outcome. This update will also ask why common pathogenic variants accumulate in certain brain regions, e.g., MTOR in the frontal lobe, and BRAF in the temporal lobe. Finally, I will highlight the ongoing discussion addressing commonalities between temporal lobe epilepsy and Alzheimer's disease, the impact of adult neurogenesis and gliogenesis for the initiation and progression of temporal lobe seizures in the human brain as well as the immunopathogenesis of glutamic acid decarboxylase antibody associated temporal lobe epilepsy as a meaningful disease entity. This review will update the reader on some of these fascinating publications from 2022 and 2023 which were selected carefully, yet subjectively, by the author.
Collapse
Affiliation(s)
- Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Germany
| |
Collapse
|
13
|
Kumari S, Brewster AL. Exploring Dendritic and Spine Structural Profiles in Epilepsy: Insights From Human Studies and Experimental Animal Models. Epilepsy Curr 2024; 24:40-46. [PMID: 38327540 PMCID: PMC10846509 DOI: 10.1177/15357597231218603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024] Open
Abstract
Dendrites are tree-like structures with tiny spines specialized to receive excitatory synaptic transmission. Spino-dendritic plasticity, driven by neural activity, underlies the maintenance of neuronal connections crucial for proper circuit function. Abnormalities in dendritic morphology are frequently seen in epilepsy. However, the exact etiology or functional implications are not yet known. Therefore, to better comprehend the structure-function significance of this dendritic pathology in epilepsy, it is necessary to identify the common spino-dendritic disturbances present in both human and experimental models. Here, we describe the dendritic and spine structural profiles found across human refractory epilepsy as well as in animal models of developmental, acquired, and genetic epilepsies.
Collapse
Affiliation(s)
- Shikha Kumari
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX, USA
| | - Amy L. Brewster
- Department of Biological Sciences, Dedman College of Humanities and Sciences, Southern Methodist University, Dallas, TX, USA
| |
Collapse
|
14
|
Dainelli A, Iacomino M, Rossato S, Bugin S, Traverso M, Severino M, Gustincich S, Capra V, Di Duca M, Zara F, Scala M, Striano P. Refining the electroclinical spectrum of NPRL3-related epilepsy: A novel multiplex family and literature review. Epilepsia Open 2023; 8:1314-1330. [PMID: 37491868 PMCID: PMC10690669 DOI: 10.1002/epi4.12798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 07/17/2023] [Indexed: 07/27/2023] Open
Abstract
OBJECTIVE NPRL3-related epilepsy (NRE) is an emerging condition set within the wide GATOR-1 spectrum with a particularly heterogeneous and elusive phenotypic expression. Here, we delineated the genotype-phenotype spectrum of NRE, reporting an illustrative familial case and reviewing pertinent literature. METHODS Through exome sequencing (ES), we investigated a 12-year-old girl with recurrent focal motor seizures during sleep, suggestive of sleep-related hypermotor epilepsy (SHE), and a family history of epilepsy in siblings. Variant segregation analysis was performed by Sanger sequencing. All previously published NRE patients were thoroughly reviewed and their electroclinical features were analyzed and compared with the reported subjects. RESULTS In the proband, ES detected the novel NPRL3 frameshift variant (NM_001077350.3): c.151_152del (p.Thr51Glyfs*5). This variant is predicted to cause a loss of function and segregated in one affected brother. The review of 76 patients from 18 publications revealed the predominance of focal-onset seizures (67/74-90%), with mainly frontal and frontotemporal (32/67-47.7%), unspecified (19/67-28%), or temporal (9/67-13%) onset. Epileptic syndromes included familial focal epilepsy with variable foci (FFEVF) (29/74-39%) and SHE (11/74-14.9%). Fifteen patients out of 60 (25%) underwent epilepsy surgery, 11 of whom achieved complete seizure remission (11/15-73%). Focal cortical dysplasia (FCD) type 2A was the most frequent histopathological finding. SIGNIFICANCE We reported an illustrative NPRL3-related epilepsy (NRE) family with incomplete penetrance. This condition consists of a heterogeneous spectrum of clinical and neuroradiological features. Focal-onset motor seizures are predominant, and almost half of the cases fulfill the criteria for SHE or FFEVF. MRI-negative cases are prevalent, but the association with malformations of cortical developments (MCDs) is significant, especially FCD type 2a. The beneficial impact of epilepsy surgery in patients with MCD-related epilepsy further supports the inclusion of brain MRI in the workup of NRE patients.
Collapse
Affiliation(s)
- Alice Dainelli
- Pediatric Neurology and Muscular Diseases UnitIRCCS Istituto Giannina GasliniGenoaItaly
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthUniversità Degli Studi di GenovaGenoaItaly
| | | | - Sara Rossato
- U.O.C. Pediatria, Ospedale San BortoloVicenzaItaly
| | | | - Monica Traverso
- Pediatric Neurology and Muscular Diseases UnitIRCCS Istituto Giannina GasliniGenoaItaly
| | | | | | - Valeria Capra
- UOC Genetica MedicaIRCCS Istituto Giannina GasliniGenoaItaly
| | - Marco Di Duca
- UOC Genetica MedicaIRCCS Istituto Giannina GasliniGenoaItaly
| | - Federico Zara
- UOC Genetica MedicaIRCCS Istituto Giannina GasliniGenoaItaly
| | - Marcello Scala
- Pediatric Neurology and Muscular Diseases UnitIRCCS Istituto Giannina GasliniGenoaItaly
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthUniversità Degli Studi di GenovaGenoaItaly
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases UnitIRCCS Istituto Giannina GasliniGenoaItaly
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child HealthUniversità Degli Studi di GenovaGenoaItaly
| |
Collapse
|
15
|
Krochmalnek E, Accogli A, St-Onge J, Addour-Boudrahem N, Prakash G, Kim SH, Brunette-Clement T, Alhajaj G, Mougharbel L, Bruneau E, Myers KA, Dubeau F, Karamchandani J, Farmer JP, Atkinson J, Hall J, Chantal Poulin C, Rosenblatt B, Lafond-Lapalme J, Weil A, Fallet-Bianco C, Albrecht S, Sonenberg N, Riviere JB, Dudley RW, Srour M. mTOR Pathway Somatic Pathogenic Variants in Focal Malformations of Cortical Development: Novel Variants, Topographic Mapping, and Clinical Outcomes. Neurol Genet 2023; 9:e200103. [PMID: 37900581 PMCID: PMC10602370 DOI: 10.1212/nxg.0000000000200103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 09/06/2023] [Indexed: 10/31/2023]
Abstract
Background and Objectives Somatic and germline pathogenic variants in genes of the mammalian target of rapamycin (mTOR) signaling pathway are a common mechanism underlying a subset of focal malformations of cortical development (FMCDs) referred to as mTORopathies, which include focal cortical dysplasia (FCD) type II, subtypes of polymicrogyria, and hemimegalencephaly. Our objective is to screen resected FMCD specimens with mTORopathy features on histology for causal somatic variants in mTOR pathway genes, describe novel pathogenic variants, and examine the variant distribution in relation to neuroimaging, histopathologic classification, and clinical outcomes. Methods We performed ultra-deep sequencing using a custom HaloPlexHS Target Enrichment kit in DNA from 21 resected fresh-frozen histologically confirmed FCD type II, tuberous sclerosis complex, or hemimegalencephaly specimens. We mapped the variant alternative allele frequency (AAF) across the resected brain using targeted ultra-deep sequencing in multiple formalin-fixed paraffin-embedded tissue blocks. We also functionally validated 2 candidate somatic MTOR variants and performed targeted RNA sequencing to validate a splicing defect associated with a novel DEPDC5 variant. Results We identified causal mTOR pathway gene variants in 66.7% (14/21) of patients, of which 13 were somatic with AAF ranging between 0.6% and 12.0%. Moreover, the AAF did not predict balloon cell presence. Favorable seizure outcomes were associated with genetically clear resection borders. Individuals in whom a causal somatic variant was undetected had excellent postsurgical outcomes. In addition, we demonstrate pathogenicity of the novel c.4373_4375dupATG and candidate c.7499T>A MTOR variants in vitro. We also identified a novel germline aberrant splice site variant in DEPDC5 (c.2802-1G>C). Discussion The AAF of somatic pathogenic variants correlated with the topographic distribution, histopathology, and postsurgical outcomes. Moreover, cortical regions with absent histologic FCD features had negligible or undetectable pathogenic variant loads. By contrast, specimens with frank histologic abnormalities had detectable pathogenic variant loads, which raises important questions as to whether there is a tolerable variant threshold and whether surgical margins should be clean, as performed in tumor resections. In addition, we describe 2 novel pathogenic variants, expanding the mTORopathy genetic spectrum. Although most pathogenic somatic variants are located at mutation hotspots, screening the full-coding gene sequence remains necessary in a subset of patients.
Collapse
Affiliation(s)
- Eric Krochmalnek
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Andrea Accogli
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Judith St-Onge
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Nassima Addour-Boudrahem
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Gyan Prakash
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Sung-Hoon Kim
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Tristan Brunette-Clement
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Ghadd Alhajaj
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Lina Mougharbel
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Elena Bruneau
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Kenneth A Myers
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Francois Dubeau
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Jason Karamchandani
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Jean-Pierre Farmer
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Jeffrey Atkinson
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Jeffrey Hall
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Chantal Chantal Poulin
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Bernard Rosenblatt
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Joel Lafond-Lapalme
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Alexander Weil
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Catherine Fallet-Bianco
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Steffen Albrecht
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Nahum Sonenberg
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Jean-Baptiste Riviere
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Roy W Dudley
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| | - Myriam Srour
- From the Research Institute of the McGill University Health Centre (E.K., J.S.-O., N.A.-B., L.M., E.B., K.A.M., J.L.-L., J.-B.R., R.W.D., M.S.); Integrated Program in Neuroscience (E.K.), McGill University; Department of Specialized Medicine (A.A.), McGill University Health Centre; Department of Human Genetics (A.A., J.-B.R.), Faculty of Medicine; Goodman Cancer Centre (G.P., S.-H.K., N.S.), Department of Biochemistry, McGill University; Department of Pediatric Neurosurgery (T.B.-C., A.W.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal; Division of Pediatric Neurology (G.A., K.A.M., C.C.P., M.S.), Department of Pediatrics, McGill University, Montreal, Quebec, Canada; Department of Pediatrics (G.A.), Unaizah College of Medicine and Medical Sciences, Qassim University, Saudi Arabia; Department of Neurology and Neurosurgery (K.A.M., F.D., J.H., C.C.P., M.S.), McGill University Health Centre; Department of Pathology (J.K., S.A.), McGill University; Division of Neurosurgery (J.-P.F., J.A., R.W.D.), Department of Pediatric Surgery, McGill University Health Center; McGill University (B.R.); Department of Pathology (C.F.-B.), Centre Hospitalier Universitaire Sainte-Justine, University of Montreal, Quebec, Canada
| |
Collapse
|
16
|
Okoh J, Mays J, Bacq A, Oses-Prieto JA, Tyanova S, Chen CJ, Imanbeyev K, Doladilhe M, Zhou H, Jafar-Nejad P, Burlingame A, Noebels J, Baulac S, Costa-Mattioli M. Targeted suppression of mTORC2 reduces seizures across models of epilepsy. Nat Commun 2023; 14:7364. [PMID: 37963879 PMCID: PMC10645975 DOI: 10.1038/s41467-023-42922-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 10/26/2023] [Indexed: 11/16/2023] Open
Abstract
Epilepsy is a neurological disorder that poses a major threat to public health. Hyperactivation of mTOR complex 1 (mTORC1) is believed to lead to abnormal network rhythmicity associated with epilepsy, and its inhibition is proposed to provide some therapeutic benefit. However, mTOR complex 2 (mTORC2) is also activated in the epileptic brain, and little is known about its role in seizures. Here we discover that genetic deletion of mTORC2 from forebrain neurons is protective against kainic acid-induced behavioral and EEG seizures. Furthermore, inhibition of mTORC2 with a specific antisense oligonucleotide robustly suppresses seizures in several pharmacological and genetic mouse models of epilepsy. Finally, we identify a target of mTORC2, Nav1.2, which has been implicated in epilepsy and neuronal excitability. Our findings, which are generalizable to several models of human seizures, raise the possibility that inhibition of mTORC2 may serve as a broader therapeutic strategy against epilepsy.
Collapse
Affiliation(s)
- James Okoh
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | - Jacqunae Mays
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Alexandre Bacq
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Juan A Oses-Prieto
- Departments of Chemistry and Pharmaceutical Chemistry, University of California San Fransisco, San Fransisco, CA, USA
| | - Stefka Tyanova
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | - Chien-Ju Chen
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Novartis Inc, Boston, MA, USA
| | - Khalel Imanbeyev
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
| | - Marion Doladilhe
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Hongyi Zhou
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA
| | | | - Alma Burlingame
- Departments of Chemistry and Pharmaceutical Chemistry, University of California San Fransisco, San Fransisco, CA, USA
| | - Jeffrey Noebels
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Stephanie Baulac
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013, Paris, France
| | - Mauro Costa-Mattioli
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
- Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA.
- Altos Labs Inc, Bay Area Institute, Redwood City, CA, USA.
| |
Collapse
|
17
|
Honke J, Hoffmann L, Coras R, Kobow K, Leu C, Pieper T, Hartlieb T, Bien CG, Woermann F, Cloppenborg T, Kalbhenn T, Gaballa A, Hamer H, Brandner S, Rössler K, Dörfler A, Rampp S, Lemke JR, Baldassari S, Baulac S, Lal D, Nürnberg P, Blümcke I. Deep histopathology genotype-phenotype analysis of focal cortical dysplasia type II differentiates between the GATOR1-altered autophagocytic subtype IIa and MTOR-altered migration deficient subtype IIb. Acta Neuropathol Commun 2023; 11:179. [PMID: 37946310 PMCID: PMC10633947 DOI: 10.1186/s40478-023-01675-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/21/2023] [Indexed: 11/12/2023] Open
Abstract
Focal cortical dysplasia type II (FCDII) is the most common cause of drug-resistant focal epilepsy in children. Herein, we performed a deep histopathology-based genotype-phenotype analysis to further elucidate the clinico-pathological and genetic presentation of FCDIIa compared to FCDIIb. Seventeen individuals with histopathologically confirmed diagnosis of FCD ILAE Type II and a pathogenic variant detected in brain derived DNA whole-exome sequencing or mTOR gene panel sequencing were included in this study. Clinical data were directly available from each contributing centre. Histopathological analyses were performed from formalin-fixed, paraffin-embedded tissue samples using haematoxylin-eosin and immunohistochemistry for NF-SMI32, NeuN, pS6, p62, and vimentin. Ten individuals carried loss-of-function variants in the GATOR1 complex encoding genes DEPDC5 (n = 7) and NPRL3 (n = 3), or gain-of-function variants in MTOR (n = 7). Whereas individuals with GATOR1 variants only presented with FCDIIa, i.e., lack of balloon cells, individuals with MTOR variants presented with both histopathology subtypes, FCDIIa and FCDIIb. Interestingly, 50% of GATOR1-positive cases showed a unique and predominantly vacuolizing phenotype with p62 immunofluorescent aggregates in autophagosomes. All cases with GATOR1 alterations had neurosurgery in the frontal lobe and the majority was confined to the cortical ribbon not affecting the white matter. This pattern was reflected by subtle or negative MRI findings in seven individuals with GATOR1 variants. Nonetheless, all individuals were seizure-free after surgery except four individuals carrying a DEPDC5 variant. We describe a yet underrecognized genotype-phenotype correlation of GATOR1 variants with FCDIIa in the frontal lobe. These lesions were histopathologically characterized by abnormally vacuolizing cells suggestive of an autophagy-altered phenotype. In contrast, individuals with FCDIIb and brain somatic MTOR variants showed larger lesions on MRI including the white matter, suggesting compromised neural cell migration.
Collapse
Affiliation(s)
- Jonas Honke
- Department of Neuropathology, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
- Partner of the European Reference Network (ERN) EpiCARE, Barcelona, Spain
| | - Lucas Hoffmann
- Department of Neuropathology, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
- Partner of the European Reference Network (ERN) EpiCARE, Barcelona, Spain
| | - Roland Coras
- Department of Neuropathology, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
- Partner of the European Reference Network (ERN) EpiCARE, Barcelona, Spain
| | - Katja Kobow
- Department of Neuropathology, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
- Partner of the European Reference Network (ERN) EpiCARE, Barcelona, Spain
| | - Costin Leu
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, USA
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, UK
- Department of Neurology, McGovern Medical School, UTHealth Houston, University of Texas, Houston, USA
| | - Tom Pieper
- Center for Pediatric Neurology, Neurorehabilitation, and Epileptology, Schoen-Clinic, Vogtareuth, Germany
| | - Till Hartlieb
- Center for Pediatric Neurology, Neurorehabilitation, and Epileptology, Schoen-Clinic, Vogtareuth, Germany
- Research Institute for Rehabilitation, Transition, and Palliation, Paracelsus Medical University, Salzburg, Austria
| | - Christian G Bien
- Department of Epileptology (Krankenhaus Mara), Medical School, Bielefeld University, Bielefeld, Germany
| | - Friedrich Woermann
- Department of Epileptology (Krankenhaus Mara), Medical School, Bielefeld University, Bielefeld, Germany
| | - Thomas Cloppenborg
- Department of Epileptology (Krankenhaus Mara), Medical School, Bielefeld University, Bielefeld, Germany
| | - Thilo Kalbhenn
- Department of Epileptology (Krankenhaus Mara), Medical School, Bielefeld University, Bielefeld, Germany
- Department of Neurosurgery (Evangelisches Klinikum Bethel), Medical School, Bielefeld University, Bielefeld, Germany
| | - Ahmed Gaballa
- Department of Epileptology (Krankenhaus Mara), Medical School, Bielefeld University, Bielefeld, Germany
| | - Hajo Hamer
- Partner of the European Reference Network (ERN) EpiCARE, Barcelona, Spain
- Epilepsy Center, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Sebastian Brandner
- Department of Neurosurgery, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Karl Rössler
- Department of Neurosurgery, Medical University of Vienna, Vienna General Hospital, Vienna, Austria
| | - Arnd Dörfler
- Department of Neuroradiology, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Stefan Rampp
- Department of Neurosurgery, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
- Department of Neuroradiology, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig, Germany
| | - Sara Baldassari
- Inserm, CNRS, APHP, Institut du Cerveau - Paris Brain Institute - ICM, Hôpital de La Pitié Salpêtrière, Sorbonne Université, Paris, France
| | - Stéphanie Baulac
- Inserm, CNRS, APHP, Institut du Cerveau - Paris Brain Institute - ICM, Hôpital de La Pitié Salpêtrière, Sorbonne Université, Paris, France
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, USA
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T, Cambridge, MA, 02142, USA
- Cologne Center for Genomics (CCG), Medical Faculty of the University of Cologne, University Hospital of Cologne, 50931, Cologne, Germany
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, UK
- Department of Neurology, McGovern Medical School, UTHealth Houston, University of Texas, Houston, USA
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), Medical Faculty of the University of Cologne, University Hospital of Cologne, 50931, Cologne, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, Universitätsklinikum Erlangen, FAU Erlangen-Nürnberg, Erlangen, Germany.
- Partner of the European Reference Network (ERN) EpiCARE, Barcelona, Spain.
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T, Cambridge, MA, 02142, USA.
| |
Collapse
|
18
|
Straka B, Splitkova B, Vlckova M, Tesner P, Rezacova H, Krskova L, Koblizek M, Kyncl M, Maulisova A, Bukacova K, Uhrova-Meszarosova A, Musilova A, Kudr M, Ebel M, Belohlavkova A, Jahodova A, Liby P, Tichy M, Jezdik P, Zamecnik J, Aronica E, Krsek P. Genetic testing in children enrolled in epilepsy surgery program. A real-life study. Eur J Paediatr Neurol 2023; 47:80-87. [PMID: 37812946 DOI: 10.1016/j.ejpn.2023.09.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023]
Abstract
OBJECTIVE Although genetic causes of drug-resistant focal epilepsy and selected focal malformations of cortical development (MCD) have been described, a limited number of studies comprehensively analysed genetic diagnoses in patients undergoing pre-surgical evaluation, their outcomes and the effect of genetic diagnosis on surgical strategy. METHODS We analysed a prospective cohort of children enrolled in epilepsy surgery program over January 2018-July 2022. The majority of patients underwent germline and/or somatic genetic testing. We searched for predictors of surgical outcome and positive result of germline genetic testing. RESULTS Ninety-five patients were enrolled in epilepsy surgery program and 64 underwent resective epilepsy surgery. We ascertained germline genetic diagnosis in 13/74 patients having underwent germline gene testing (pathogenic or likely pathogenic variants in CHRNA4, NPRL3, DEPDC5, FGF12, GRIA2, SZT2, STXBP1) and identified three copy number variants. Thirty-five patients underwent somatic gene testing; we detected 10 pathogenic or likely pathogenic variants in genes SLC35A2, PTEN, MTOR, DEPDC5, NPRL3. Germline genetic diagnosis was significantly associated with the diagnosis of focal epilepsy with unknown seizure onset. SIGNIFICANCE Germline and somatic gene testing can ascertain a definite genetic diagnosis in a significant subgroup of patients in epilepsy surgery programs. Diagnosis of focal genetic epilepsy may tip the scales against the decision to proceed with invasive EEG study or surgical resection; however, selected patients with genetic focal epilepsies associated with MCD may benefit from resective epilepsy surgery and therefore, a genetic diagnosis does not disqualify patients from presurgical evaluation and epilepsy surgery.
Collapse
Affiliation(s)
- Barbora Straka
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Barbora Splitkova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Marketa Vlckova
- Department of Biology and Medical Genetics, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Pavel Tesner
- Department of Biology and Medical Genetics, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Hana Rezacova
- Department of Biology and Medical Genetics, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Lenka Krskova
- Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Miroslav Koblizek
- Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Martin Kyncl
- Department of Radiology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Alice Maulisova
- Department of Clinical Psychology, Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Katerina Bukacova
- Department of Clinical Psychology, Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Anna Uhrova-Meszarosova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Alena Musilova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Martin Kudr
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Matyas Ebel
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Anezka Belohlavkova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Alena Jahodova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Petr Liby
- Department of Neurosurgery, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Michal Tichy
- Department of Neurosurgery, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Petr Jezdik
- Faculty of Electrical Engineering, Department of Circuit Theory, Czech Technical University in Prague, Technicka 2, Praha 6, 166 27, Czech Republic.
| | - Josef Zamecnik
- Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Eleonora Aronica
- Amsterdam UMC Location University of Amsterdam, Department of Neuropathology, Amsterdam Neuroscience, the Netherlands; Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, the Netherlands.
| | - Pavel Krsek
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Full Member of the ERN EpiCARE, V Uvalu 84, 15006, Prague, Czech Republic.
| |
Collapse
|
19
|
Kao HY, Yao Y, Yang T, Ziobro J, Zylinski M, Mir MY, Hu S, Cao R, Borna NN, Banerjee R, Parent JM, Wang S, Leventhal DK, Li P, Wang Y. Sudden Unexpected Death in Epilepsy and Respiratory Defects in a Mouse Model of DEPDC5-Related Epilepsy. Ann Neurol 2023; 94:812-824. [PMID: 37606181 PMCID: PMC10592102 DOI: 10.1002/ana.26773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/23/2023]
Abstract
OBJECTIVES DEPDC5 is a common causative gene in familial focal epilepsy with or without malformations of cortical development. Its pathogenic variants also confer a significantly higher risk for sudden unexpected death in epilepsy (SUDEP), providing opportunities to investigate the pathophysiology intersecting neurodevelopment, epilepsy, and cardiorespiratory function. There is an urgent need to gain a mechanistic understanding of DEPDC5-related epilepsy and SUDEP, identify biomarkers for patients at high risk, and develop preventive interventions. METHODS Depdc5 was specifically deleted in excitatory or inhibitory neurons in the mouse brain to determine neuronal subtypes that drive epileptogenesis and SUDEP. Electroencephalogram (EEG), cardiac, and respiratory recordings were performed to determine cardiorespiratory phenotypes associated with SUDEP. Baseline respiratory function and the response to hypoxia challenge were also studied in these mice. RESULTS Depdc5 deletion in excitatory neurons in cortical layer 5 and dentate gyrus caused frequent generalized tonic-clonic seizures and SUDEP in young adult mice, but Depdc5 deletion in cortical interneurons did not. EEG suppression immediately following ictal offset was observed in fatal and non-fatal seizures, but low amplitude rhythmic theta frequency activity was lost only in fatal seizures. In addition, these mice developed baseline respiratory dysfunction prior to SUDEP, during which ictal apnea occurred long before terminal cardiac asystole. INTERPRETATION Depdc5 deletion in excitatory neurons is sufficient to cause DEPDC5-related epilepsy and SUDEP. Ictal apnea and respiratory dysregulation play critical roles in SUDEP. Our study also provides a novel mouse model to investigate the underlying mechanisms of DEPDC5-related epilepsy and SUDEP. ANN NEUROL 2023;94:812-824.
Collapse
Affiliation(s)
- Hsin-Yi Kao
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Yilong Yao
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Tao Yang
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Julie Ziobro
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Mary Zylinski
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Mohd Yaqub Mir
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Shuntong Hu
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Runnan Cao
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | | | - Rajat Banerjee
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Jack M. Parent
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
- VA Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
- Michgian Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA
| | - Shuo Wang
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Daniel K. Leventhal
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
- VA Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
- Parkinson Disease Foundation Research Center of Excellence, University of Michigan, Ann Arbor, MI, USA
| | - Peng Li
- Michgian Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Biologic and Material Sciences, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Yu Wang
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
- VA Ann Arbor Healthcare System, Ann Arbor, MI 48105, USA
- Michgian Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
20
|
Hadzsiev K, Hegyi M, Fogarasi A, Bodó-Baltavári T, Zsigmond A, Maász A, Szabó A, Till Á. Observation of a Possible Successful Treatment of DEPDC5-Related Epilepsy with mTOR Inhibitor. Neuropediatrics 2023; 54:344-346. [PMID: 37263295 PMCID: PMC10506865 DOI: 10.1055/a-2104-1614] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 04/18/2023] [Indexed: 06/03/2023]
Abstract
The mechanistic target of the rapamycin signaling pathway serves as a central regulator of cell metabolism, growth, proliferation, and survival. In its regulation, the GTPase-activating protein activity toward Rags1 complex has an inhibitory effect. Mutations in genes encoding this complex protein are among the most common abnormalities in focal epilepsies. Within these mutations, the mutations affecting the DEPDC5 gene have been associated with different autosomal dominantly inherited epilepsy types. Due to the limited data available on mTOR inhibitor therapy in nontuberous sclerosis complex epileptic patients, here we present the clinical management of a patient with intractable epilepsy, skin hypopigmentation, and a DEPDC5 variant. The patient's phenotype is compatible with a nonlesional DEPDC5-related epileptic encephalopathy. We initiated compassionate, off-label everolimus treatment as the patient's condition continuously deteriorated. Due to bilateral pneumonia occurring at the beginning of the treatment, it was temporarily discontinued, and resumed in half the dose. Follow-up examination after 18 months showed a 90% reduction in seizure frequency with moderate improvement in attention function and nutritional status. Our case report emphasizes the importance of early genetic testing in patients with epileptic encephalopathy. Clinical consequences of mammalian target of rapamycin complex 1 (mTORC1) upregulation may be amenable to tailored treatment with mTOR inhibitors. A clinical trial on an international scale would be needed to draw conclusions.
Collapse
Affiliation(s)
- Kinga Hadzsiev
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| | - Márta Hegyi
- Bethesda Children's Hospital, Epilepsy Center, Budapest, Hungary
| | - András Fogarasi
- Bethesda Children's Hospital, Epilepsy Center, Budapest, Hungary
| | | | - Anna Zsigmond
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| | - Anita Maász
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| | - András Szabó
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| | - Ágnes Till
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| |
Collapse
|
21
|
Rastin C, Schenkel LC, Sadikovic B. Complexity in Genetic Epilepsies: A Comprehensive Review. Int J Mol Sci 2023; 24:14606. [PMID: 37834053 PMCID: PMC10572646 DOI: 10.3390/ijms241914606] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
Epilepsy is a highly prevalent neurological disorder, affecting between 5-8 per 1000 individuals and is associated with a lifetime risk of up to 3%. In addition to high incidence, epilepsy is a highly heterogeneous disorder, with variation including, but not limited to the following: severity, age of onset, type of seizure, developmental delay, drug responsiveness, and other comorbidities. Variable phenotypes are reflected in a range of etiologies including genetic, infectious, metabolic, immune, acquired/structural (resulting from, for example, a severe head injury or stroke), or idiopathic. This review will focus specifically on epilepsies with a genetic cause, genetic testing, and biomarkers in epilepsy.
Collapse
Affiliation(s)
- Cassandra Rastin
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
| | - Laila C. Schenkel
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
| | - Bekim Sadikovic
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON N6A 5W9, Canada
- Department of Pathology and Laboratory Medicine, Western University, London, ON N6A 3K7, Canada
| |
Collapse
|
22
|
Wang H, Liu W, Zhang Y, Liu Q, Cai L, Jiang Y. Seizure features and outcomes in 50 children with GATOR1 variants: A retrospective study, more favorable for epilepsy surgery. Epilepsia Open 2023; 8:969-979. [PMID: 37259768 PMCID: PMC10472406 DOI: 10.1002/epi4.12770] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/26/2023] [Indexed: 06/02/2023] Open
Abstract
OBJECTIVES To summarize the clinical features of epilepsy related to DEPDC5, NPRL2, and NPRL3 genes encoding the GATOR1 complex in children and to evaluate the factors affecting the prognosis of these epilepsies. METHODS In this retrospective study, we reviewed the clinical and genetic characteristics of children with epilepsy related to GATOR1 variants who were admitted to the Peking University First Hospital between January 2016 and December 2021. Potential prognostic factors were assessed by comparing children with and without ongoing seizures. RESULTS Fifty probands, including 31 boys and 19 girls were recruited. The median age at onset of epilepsy was 4 months, and 64% of patients had early-onset epilepsy (≤1 year). The most frequent epileptic seizure type was focal seizure (86%). Among the 50 patients, only six were with de novo variants. According to the novel classification framework for GATOR1 variants, 36 patients were with pathogenic variants and 14 with likely pathogenic variants. DEPDC5 variants were found in 37 patients, NPRL3 in 9, and NPRL2 in 4. The phenotype was similar among the probands, with variants in DEPDC5, NRPL2, or NPRL3. 76% (38/50) of epilepsy related to GATOR1 variants was neuroimaging positive, including brain MRI positive in 31 patients, and MRI combined F-18-fluorodeoxyglucose positron emission tomography positive in the other seven patients. Twenty-seven patients underwent epilepsy surgery. In total, after initial antiseizure medications alone, 92% (46/50) of patients were drug-resistant epilepsies, only 8% (4/50) of the probands became seizure-free but seizure-free (≥6 m) occurred in 92.6% (25/27) of patients with drug-resistant epilepsy after epilepsy surgery at the last follow-up. Patients undergoing epilepsy surgery had better epilepsy prognosis. SIGNIFICANCE Epilepsy related to GATOR1 variants had high possibility to be drug-resistant epilepsy and to have positive neuroimaging finding. Epilepsy surgery is the only favorable factor for better seizure prognosis in this kind epilepsy.
Collapse
Affiliation(s)
- Hao Wang
- Department of PediatricsPeking University First HospitalBeijingChina
| | - Wenwei Liu
- Department of PediatricsPeking University First HospitalBeijingChina
| | - Yuehua Zhang
- Department of PediatricsPeking University First HospitalBeijingChina
- Pediatric Epilepsy CenterPeking University First HospitalBeijingChina
| | - Qingzhu Liu
- Department of PediatricsPeking University First HospitalBeijingChina
- Pediatric Epilepsy CenterPeking University First HospitalBeijingChina
| | - Lixin Cai
- Department of PediatricsPeking University First HospitalBeijingChina
- Pediatric Epilepsy CenterPeking University First HospitalBeijingChina
| | - Yuwu Jiang
- Department of PediatricsPeking University First HospitalBeijingChina
- Pediatric Epilepsy CenterPeking University First HospitalBeijingChina
- Beijing Key Laboratory of Molecular Diagnosis and Study on Pediatric Genetic DiseasesBeijingChina
- Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning CommissionPeking UniversityBeijingChina
- Center of Epilepsy, Beijing Institute for Brain DisordersBeijingChina
| |
Collapse
|
23
|
Du S, Zeng S, Song L, Ma H, Chen R, Luo J, Wang X, Ma T, Xu X, Sun H, Yi P, Guo J, Huang Y, Liu M, Wang T, Liao WP, Zhang L, Liu JY, Tang B. Functional characterization of novel NPRL3 mutations identified in three families with focal epilepsy. SCIENCE CHINA. LIFE SCIENCES 2023; 66:2152-2166. [PMID: 37071290 DOI: 10.1007/s11427-022-2313-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/01/2023] [Indexed: 04/19/2023]
Abstract
Focal epilepsy accounts for 60% of all forms of epilepsy, but the pathogenic mechanism is not well understood. In this study, three novel mutations in NPRL3 (nitrogen permease regulator-like 3), c.937_945del, c.1514dupC and 6,706-bp genomic DNA (gDNA) deletion, were identified in three families with focal epilepsy by linkage analysis, whole exome sequencing (WES) and Sanger sequencing. NPRL3 protein is a component of the GATOR1 complex, a major inhibitor of mTOR signaling. These mutations led to truncation of the NPRL3 protein and hampered the binding between NPRL3 and DEPDC5, which is another component of the GATOR1 complex. Consequently, the mutant proteins enhanced mTOR signaling in cultured cells, possibly due to impaired inhibition of mTORC1 by GATOR1. Knockdown of nprl3 in Drosophila resulted in epilepsy-like behavior and abnormal synaptic development. Taken together, these findings expand the genotypic spectrum of NPRL3-associated focal epilepsy and provide further insight into how NPRL3 mutations lead to epilepsy.
Collapse
Affiliation(s)
- Shiyue Du
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Sheng Zeng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, China
- Department of Geriatrics, The Second Xiangya Hospital, Central South University, Changsha, 410011, China
| | - Li Song
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Hongying Ma
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Rui Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Junyu Luo
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Xu Wang
- National Reference Laboratory of Veterinary Drug Residues and MAO Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan, 430070, China
| | - Tingbin Ma
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Xuan Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Hao Sun
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Ping Yi
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Jifeng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Yaling Huang
- Department of Neurology, Union Hospital of HUST, Wuhan, 430022, China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China
| | - Tao Wang
- Department of Neurology, Union Hospital of HUST, Wuhan, 430022, China
| | - Wei-Ping Liao
- Institute of Neuroscience and Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University; Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou Medical University, Guangzhou, 510260, China
| | - Luoying Zhang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
- Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration, Wuhan, 430022, China.
| | - Jing Yu Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, China.
- Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, 410008, China.
| |
Collapse
|
24
|
Boßelmann CM, Leu C, Lal D. Technological and computational approaches to detect somatic mosaicism in epilepsy. Neurobiol Dis 2023:106208. [PMID: 37343892 DOI: 10.1016/j.nbd.2023.106208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 06/03/2023] [Accepted: 06/16/2023] [Indexed: 06/23/2023] Open
Abstract
Lesional epilepsy is a common and severe disease commonly associated with malformations of cortical development, including focal cortical dysplasia and hemimegalencephaly. Recent advances in sequencing and variant calling technologies have identified several genetic causes, including both short/single nucleotide and structural somatic variation. In this review, we aim to provide a comprehensive overview of the methodological advancements in this field while highlighting the unresolved technological and computational challenges that persist, including ultra-low variant allele fractions in bulk tissue, low availability of paired control samples, spatial variability of mutational burden within the lesion, and the issue of false-positive calls and validation procedures. Information from genetic testing in focal epilepsy may be integrated into clinical care to inform histopathological diagnosis, postoperative prognosis, and candidate precision therapies.
Collapse
Affiliation(s)
- Christian M Boßelmann
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Costin Leu
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, UK.
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA; Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T., Cambridge, MA, USA; Cologne Center for Genomics (CCG), University of Cologne, Cologne, DE, USA
| |
Collapse
|
25
|
Checri R, Chipaux M, Ferrand-Sorbets S, Raffo E, Bulteau C, Rosenberg SD, Doladilhe M, Dorfmüller G, Adle-Biassette H, Baldassari S, Baulac S. Detection of brain somatic mutations in focal cortical dysplasia during epilepsy presurgical workup. Brain Commun 2023; 5:fcad174. [PMID: 37324239 PMCID: PMC10261848 DOI: 10.1093/braincomms/fcad174] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 04/01/2023] [Accepted: 05/31/2023] [Indexed: 06/17/2023] Open
Abstract
Brain-restricted somatic variants in genes of the mechanistic target of rapamycin signalling pathway cause focal epilepsies associated with focal cortical dysplasia type II. We hypothesized that somatic variants could be identified from trace tissue adherent to explanted stereoelectroencephalography electrodes used in the presurgical epilepsy workup to localize the epileptogenic zone. We investigated three paediatric patients with drug-resistant focal epilepsy subjected to neurosurgery. In the resected brain tissue, we identified low-level mosaic somatic mutations in AKT3 and DEPDC5 genes. We collected stereoelectroencephalography depth electrodes in the context of a second presurgical evaluation and identified 4/33 mutation-positive electrodes that were either located in the epileptogenic zone or at the border of the dysplasia. We provide the proof-of-concept that somatic mutations with low levels of mosaicism can be detected from individual stereoelectroencephalography electrodes and support a link between the mutation load and the epileptic activity. Our findings emphasize future opportunities for integrating genetic testing from stereoelectroencephalography electrodes into the presurgical evaluation of refractory epilepsy patients with focal cortical dysplasia type II to improve the patients' diagnostic journey and guide towards precision medicine.
Collapse
Affiliation(s)
| | | | - Sarah Ferrand-Sorbets
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital EpiCARE, 75019, Paris, France
| | - Emmanuel Raffo
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital EpiCARE, 75019, Paris, France
- Unité de recherche 3450 DevAH, Développement, Adaptation et Handicap, Campus Brabois-Santé, Université de Lorraine, 54505, Vandoeuvre-lès-Nancy, France
| | - Christine Bulteau
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital EpiCARE, 75019, Paris, France
- Université de Paris Cité, MC2Lab, Institut de Psychologie, F-92100 Boulogne-Billancourt, France
| | | | - Marion Doladilhe
- Sorbonne Université, Institut du Cerveau—Paris Brain Institute—ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Georg Dorfmüller
- Department of Pediatric Neurosurgery, Rothschild Foundation Hospital EpiCARE, 75019, Paris, France
| | - Homa Adle-Biassette
- Université de Paris Cité, service d’Anatomie Pathologique, APHP, Hôpital Lariboisière, DMU DREAM, UMR 1141, INSERM, 75010, Paris, France
| | | | - Stéphanie Baulac
- Correspondence to: Stéphanie Baulac Institut du Cerveau, 47 bd de l’hôpital, 75013, Paris, France E-mail:
| |
Collapse
|
26
|
Gerasimenko A, Baldassari S, Baulac S. mTOR pathway: Insights into an established pathway for brain mosaicism in epilepsy. Neurobiol Dis 2023; 182:106144. [PMID: 37149062 DOI: 10.1016/j.nbd.2023.106144] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/08/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) signaling pathway is an essential regulator of numerous cellular activities such as metabolism, growth, proliferation, and survival. The mTOR cascade recently emerged as a critical player in the pathogenesis of focal epilepsies and cortical malformations. The 'mTORopathies' comprise a spectrum of cortical malformations that range from whole brain (megalencephaly) and hemispheric (hemimegalencephaly) abnormalities to focal abnormalities, such as focal cortical dysplasia type II (FCDII), which manifest with drug-resistant epilepsies. The spectrum of cortical dysplasia results from somatic brain mutations in the mTOR pathway activators AKT3, MTOR, PIK3CA, and RHEB and from germline and somatic mutations in mTOR pathway repressors, DEPDC5, NPRL2, NPRL3, TSC1 and TSC2. The mTORopathies are characterized by excessive mTOR pathway activation, leading to a broad range of structural and functional impairments. Here, we provide a comprehensive literature review of somatic mTOR-activating mutations linked to epilepsy and cortical malformations in 292 patients and discuss the perspectives of targeted therapeutics for personalized medicine.
Collapse
Affiliation(s)
- Anna Gerasimenko
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013 Paris, France; APHP Sorbonne Université, GH Pitié Salpêtrière et Trousseau, Département de Génétique, Centre de référence "déficiences intellectuelles de causes rares", Paris, France
| | - Sara Baldassari
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Stéphanie Baulac
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013 Paris, France.
| |
Collapse
|
27
|
Kittock CM, Pilaz LJ. Advances in in utero electroporation. Dev Neurobiol 2023; 83:73-90. [PMID: 36861639 DOI: 10.1002/dneu.22910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/02/2023] [Accepted: 02/21/2023] [Indexed: 03/03/2023]
Abstract
In utero electroporation (IUE) is a technique developed in the early 2000s to transfect the neurons and neural progenitors of embryonic brains, thus enabling continued development in utero and subsequent analyses of neural development. Early IUE experiments focused on ectopic expression of plasmid DNA to analyze parameters such as neuron morphology and migration. Recent advances made in other fields, such as CRISPR/CAS9 genome editing, have been incorporated into IUE techniques as they were developed. Here, we provide a general review of the mechanics and techniques involved in IUE and explore the breadth of approaches that can be used in conjunction with IUE to study cortical development in a rodent model, with a focus on the novel advances in IUE techniques. We also highlight a few cases that exemplify the potential of IUE to study a broad range of questions in neural development.
Collapse
Affiliation(s)
- Claire M Kittock
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
- Sanford School of Medicine, University of South Dakota, Sioux Falls, South Dakota, USA
| | - Louis-Jan Pilaz
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, South Dakota, USA
- Sanford School of Medicine, University of South Dakota, Sioux Falls, South Dakota, USA
| |
Collapse
|
28
|
Auvin S, Baulac S. mTOR-therapy and targeted treatment opportunities in mTOR-related epilepsies associated with cortical malformations. Rev Neurol (Paris) 2023; 179:337-344. [PMID: 36906459 DOI: 10.1016/j.neurol.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/08/2022] [Accepted: 12/13/2022] [Indexed: 03/11/2023]
Abstract
Dysregulation of the mTOR pathway is now well documented in several neurodevelopmental disorders associated with epilepsy. Mutations of mTOR pathway genes are involved in tuberous sclerosis complex (TSC) as well as in a range of cortical malformations from hemimegalencephaly (HME) to type II focal cortical dysplasia (FCD II), leading to the concept of "mTORopathies" (mTOR pathway-related malformations). This suggests that mTOR inhibitors (notably rapamycin (sirolimus), and everolimus) could be used as antiseizure medication. In this review, we provide an overview of pharmacological treatments targeting the mTOR pathway for epilepsy based on lectures from the ILAE French Chapter meeting in October 2022 in Grenoble. There is strong preclinical evidence for the antiseizure effects of mTOR inhibitors in TSC and cortical malformation mouse models. There are also open studies on the antiseizure effects of mTOR inhibitors, as well as one phase III study showing the antiseizure effect of everolimus in TSC patients. Finally, we discuss to which extent mTOR inhibitors might have properties beyond the antiseizure effect on associated neuropsychiatric comorbidities. We also discuss a new way of treatment on the mTOR pathways.
Collapse
Affiliation(s)
- S Auvin
- Service de neurologie pédiatrique, EpiCARE ERN membre, Hôpital Robert Debré, AP-HP, Paris, France; Université Paris-Cité, Inserm NeuroDiderot, Paris, France; Institut Universitaire de France (IUF), Paris, France.
| | - S Baulac
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| |
Collapse
|
29
|
Shevlyakov AD, Kolesnikova TO, de Abreu MS, Petersen EV, Yenkoyan KB, Demin KA, Kalueff AV. Forward Genetics-Based Approaches to Understanding the Systems Biology and Molecular Mechanisms of Epilepsy. Int J Mol Sci 2023; 24:ijms24065280. [PMID: 36982355 PMCID: PMC10049737 DOI: 10.3390/ijms24065280] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/28/2023] [Accepted: 03/03/2023] [Indexed: 03/12/2023] Open
Abstract
Epilepsy is a highly prevalent, severely debilitating neurological disorder characterized by seizures and neuronal hyperactivity due to an imbalanced neurotransmission. As genetic factors play a key role in epilepsy and its treatment, various genetic and genomic technologies continue to dissect the genetic causes of this disorder. However, the exact pathogenesis of epilepsy is not fully understood, necessitating further translational studies of this condition. Here, we applied a computational in silico approach to generate a comprehensive network of molecular pathways involved in epilepsy, based on known human candidate epilepsy genes and their established molecular interactors. Clustering the resulting network identified potential key interactors that may contribute to the development of epilepsy, and revealed functional molecular pathways associated with this disorder, including those related to neuronal hyperactivity, cytoskeletal and mitochondrial function, and metabolism. While traditional antiepileptic drugs often target single mechanisms associated with epilepsy, recent studies suggest targeting downstream pathways as an alternative efficient strategy. However, many potential downstream pathways have not yet been considered as promising targets for antiepileptic treatment. Our study calls for further research into the complexity of molecular mechanisms underlying epilepsy, aiming to develop more effective treatments targeting novel putative downstream pathways of this disorder.
Collapse
Affiliation(s)
- Anton D. Shevlyakov
- Graduate Program in Bioinformatics and Genomics, Sirius University of Science and Technology, 354340 Sochi, Russia
- Neuroscience Program, Sirius University of Science and Technology, 354340 Sochi, Russia
| | | | | | | | - Konstantin B. Yenkoyan
- Neuroscience Laboratory of COBRAIN Center for Fundamental Brain Research, and Biochemistry Department, Yerevan State Medical University named after M. Heratsi, Yerevan 0025, Armenia
| | - Konstantin A. Demin
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 194021 St. Petersburg, Russia
- Correspondence: (K.A.D.); (A.V.K.); Tel.: +7-240-899-9571 (A.V.K.)
| | - Allan V. Kalueff
- Neuroscience Program, Sirius University of Science and Technology, 354340 Sochi, Russia
- Neuroscience Laboratory of COBRAIN Center for Fundamental Brain Research, and Biochemistry Department, Yerevan State Medical University named after M. Heratsi, Yerevan 0025, Armenia
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 194021 St. Petersburg, Russia
- Laboratory of Preclinical Bioscreening, Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of Russian Federation, 197758 Pesochny, Russia
- Neuroscience Group, Ural Federal University, 620002 Ekaterinburg, Russia
- Laboratory of Biopsychiatry, Scientific Research Institute of Physiology and Basic Medicine, 630117 Novosibirsk, Russia
- Correspondence: (K.A.D.); (A.V.K.); Tel.: +7-240-899-9571 (A.V.K.)
| |
Collapse
|
30
|
Kovačević M, Janković M, Branković M, Milićević O, Novaković I, Sokić D, Ristić A, Shamsani J, Vojvodić N. Novel GATOR1 variants in focal epilepsy. Epilepsy Behav 2023; 141:109139. [PMID: 36848747 DOI: 10.1016/j.yebeh.2023.109139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 02/03/2023] [Accepted: 02/05/2023] [Indexed: 02/27/2023]
Abstract
INTRODUCTION Variants in GATOR1 genes are well established in focal epilepsy syndromes. A strong association of GATOR1 variants with drug-resistant epilepsy as well as an increased risk of sudden unexplained death in epilepsy warrants developing strategies to facilitate the identification of patients who could potentially benefit from genetic testing and precision medicine. We aimed to determine the yield of GATOR1 gene sequencing in patients with focal epilepsy typically referred for genetic testing, establish novel GATOR1 variants and determine clinical, electroencephalographic, and radiological characteristics of variant carriers. PATIENTS AND METHODS Ninety-six patients with clinical suspicion of genetic focal epilepsy with previous comprehensive diagnostic epilepsy evaluation in The Neurology Clinic, University Clinical Center of Serbia, were included in the study. Sequencing was performed using a custom gene panel encompassing DEPDC5, NPRL2, and NPRL3. Variants of interest (VOI) were classified according to criteria proposed by the American College of Medical Genetics and the Association for Molecular Pathology. RESULTS Four previously unreported VOI in 4/96 (4.2%) patients were found in our cohort. Three likely pathogenic variants were determined in 3/96 (3.1%) patients, one frameshift variant in DEPDC5 in a patient with nonlesional frontal lobe epilepsy, one splicogenic DEPDC5 variant in a patient with nonlesional posterior quadrant epilepsy, and one frameshift variant in NPRL2 in a patient with temporal lobe epilepsy associated with hippocampal sclerosis. Only one VOI, a missense variant in NPRL3, found in 1/96 (1.1%) patients, was classified as a variant of unknown significance. CONCLUSION GATOR1 gene sequencing was diagnostic in 3.1% of our cohort and revealed three novel likely pathogenic variants, including a previously unreported association of temporal lobe epilepsy with hippocampal sclerosis with an NPRL2 variant. Further research is essential for a better understanding of the clinical scope of GATOR1 gene-associated epilepsy.
Collapse
Affiliation(s)
- Maša Kovačević
- Neurology Clinic, University Clinical Center of Serbia, Serbia; Faculty of Medicine, University of Belgrade, Serbia.
| | - Milena Janković
- Neurology Clinic, University Clinical Center of Serbia, Serbia
| | | | | | | | - Dragoslav Sokić
- Neurology Clinic, University Clinical Center of Serbia, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| | - Aleksandar Ristić
- Neurology Clinic, University Clinical Center of Serbia, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| | | | - Nikola Vojvodić
- Neurology Clinic, University Clinical Center of Serbia, Serbia; Faculty of Medicine, University of Belgrade, Serbia
| |
Collapse
|
31
|
Balestrini S, Barba C, Thom M, Guerrini R. Focal cortical dysplasia: a practical guide for neurologists. Pract Neurol 2023:pn-2022-003404. [PMID: 36823117 DOI: 10.1136/pn-2022-003404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2023] [Indexed: 02/25/2023]
Abstract
Focal cortical dysplasia (FCD) is a malformation of cortical development characterised by disruption of cortical cytoarchitecture. Classification of FCDs subtypes has initially been based on correlation of the histopathology with relevant clinical, electroencephalographic and neuroimaging features. A recently proposed classification update recommends a multilayered, genotype-phenotype approach, integrating findings from histopathology, genetic analysis of resected tissue and presurgical MRI. FCDs are caused either by single somatic activating mutations in MTOR pathway genes or by double-hit inactivating mutations with a constitutional and a somatic loss-of-function mutation in repressors of the signalling pathway. Mild malformation with oligodendroglial hyperplasia in epilepsy is caused by somatic pathogenic SLC35A2 mutations. FCDs most often present with drug-resistant focal epilepsy or epileptic encephalopathy. Most patients respond to surgical treatment. The use of mechanistic target of rapamycin inhibitors may complement the surgical approach. Treatment approaches and outcomes have improved with advances in neuroimaging, neurophysiology and genetics, although predictors of treatment response have only been determined in part.
Collapse
Affiliation(s)
- Simona Balestrini
- Pediatric Neurology Unit and Laboratories, Meyer Children's Hospital IRCCS, Florence, Italy .,University of Florence, Florence, Italy.,Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Carmen Barba
- Pediatric Neurology Unit and Laboratories, Meyer Children's Hospital IRCCS, Florence, Italy.,University of Florence, Florence, Italy
| | - Maria Thom
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Meyer Children's Hospital IRCCS, Florence, Italy.,University of Florence, Florence, Italy
| |
Collapse
|
32
|
Wang Y, Yu T, Blümcke I, Cai Y, Sun K, Gao R, Wang Y, Fu Y, Wang W, Wang Y, Zhang G, Piao Y. The clinico-pathological characterisation of focal cortical dysplasia type IIb genetically defined by MTOR mosaicism. Neuropathol Appl Neurobiol 2023; 49:e12874. [PMID: 36544434 DOI: 10.1111/nan.12874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 08/18/2022] [Accepted: 10/11/2022] [Indexed: 12/24/2022]
Abstract
AIMS Focal cortical dysplasia (FCD) is a major cause of drug-resistant paediatric epilepsy and is amenable to successful neurosurgical resection. FCD ILAE Type IIb is the most common FCD subtype, and brain somatic mutations affecting the mTOR pathway play a major pathogenic role. The aim of this study was to comprehensively describe the genotype-phenotype association of 20 patients with histopathologically confirmed FCDIIb using next generation sequencing (NGS) of paired blood-brain samples. METHODS Clinical and neuropathological data were retrospectively reviewed from the hospital archive. The NGS panel included 11 mTOR-pathway-related genes with maximum coverage of 2000×. The detected variants were validated by digital droplet PCR. RESULTS Pathogenic MTOR variants were identified in 10 patients (50%). Further comparison with MTOR-wildtype FCDIIb suggested a profound genotype-phenotype association characterised by (1) a non-temporal lobe lesion on MRI, (2) a larger lesion volume occupying grey and white matter (3.032 ± 1.859 cm3 vs 1.110 ± 0.856 cm3 , p = 0.014), (3) more balloon cells (50.20 ± 14.40 BC/mm2 vs 31.64 ± 30.56 BC/mm2 , p = 0.099) and dysmorphic neurons (48.72 ± 19.47DN/mm2 vs 15.28 ± 13.95DN/mm2 , p = 0.000) and (4) a positive correlation between VAF and the lesion volume (r = 0.802, p = 0.017). CONCLUSIONS Our study identified frequent MTOR mutations in the cell-rich FCDIIb phenotype, clinically characterised by a non-temporal location and large lesion volume. Comprehensive genotype-phenotype associations will help us further explore and define the broad spectrum of FCD lesions to make more targeted therapies available in the realm of epileptology.
Collapse
Affiliation(s)
- Yajie Wang
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China
| | - Tao Yu
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China.,Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.,Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Yanning Cai
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China.,Department of Neurobiology and Clinical Biobank, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ke Sun
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China.,Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.,Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Runshi Gao
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China.,Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.,Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yujiao Wang
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China
| | - Yongjuan Fu
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China
| | - Wei Wang
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China.,Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yuping Wang
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China.,Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Center of Epilepsy, Institute of Sleep and Consciousness Disorders, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Guojun Zhang
- Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China.,Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China.,Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yueshan Piao
- Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China.,National Center for Neurological Disorders, Beijing, China
| |
Collapse
|
33
|
Neurophysiological assessment of cortical activity in DEPDC5- and NPRL3-related epileptic mTORopathies. Orphanet J Rare Dis 2023; 18:11. [PMID: 36639812 PMCID: PMC9840333 DOI: 10.1186/s13023-022-02600-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/19/2022] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Mutations in the GATOR1 complex genes, DEPDC5 and NPRL3, play a major role in the development of lesional and non-lesional focal epilepsy through increased mTORC1 signalling. We aimed to assess the effects of mTORC1 hyperactivation on GABAergic inhibitory circuits, in 3 and 5 individuals carrying DEPDC5 and NPRL3 mutations respectively using a multimodal approach including transcranial magnetic stimulation (TMS), magnetic resonance spectroscopy (MRS), and electroencephalography (EEG). RESULTS Inhibitory functions probed by TMS and MRS showed no effect of mutations on cortical GABAergic receptor-mediated inhibition and GABA concentration, in both cortical and subcortical regions. However, stronger EEG theta oscillations and stronger and more synchronous gamma oscillations were observed in DEPDC5 and NPRL3 mutations carriers. CONCLUSIONS These results suggest that DEPDC5 and NPRL3-related epileptic mTORopathies may not directly modulate GABAergic functions but are nonetheless characterized by a stronger neural entrainment that may be reflective of a cortical hyperexcitability mediated by increased mTORC1 signaling.
Collapse
|
34
|
The Power of Clinical Diagnosis for Deciphering Complex Genetic Mechanisms in Rare Diseases. Genes (Basel) 2023; 14:genes14010196. [PMID: 36672937 PMCID: PMC9858967 DOI: 10.3390/genes14010196] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/05/2023] [Accepted: 01/09/2023] [Indexed: 01/13/2023] Open
Abstract
Complex genetic disease mechanisms, such as structural or non-coding variants, currently pose a substantial difficulty in frontline diagnostic tests. They thus may account for most unsolved rare disease patients regardless of the clinical phenotype. However, the clinical diagnosis can narrow the genetic focus to just a couple of genes for patients with well-established syndromes defined by prominent physical and/or unique biochemical phenotypes, allowing deeper analyses to consider complex genetic origin. Then, clinical-diagnosis-driven genome sequencing strategies may expedite the development of testing and analytical methods to account for complex disease mechanisms as well as to advance functional assays for the confirmation of complex variants, clinical management, and the development of new therapies.
Collapse
|
35
|
Assessment of Dynein-Mediated Nuclear Migration in the Developing Cortex by Live-Tissue Microscopy. Methods Mol Biol 2023; 2623:61-71. [PMID: 36602679 DOI: 10.1007/978-1-0716-2958-1_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
During development of the cerebral cortex, neuroepithelial and radial glial cells undergo an oscillatory nuclear movement throughout their cell cycle, termed interkinetic nuclear migration. The nucleus of postmitotic neurons derived from these neural stem cells also translocates in a saltatory manner to enable neuronal migration toward the cortical plate. In these processes, various molecular motors, including cytoplasmic dynein, myosin II, and kinesins, are the driving force for nuclear migration at different stages. Despite efforts made to understand the mechanism regulating cortical development over decades, novel gene mutations discovered in neurodevelopmental disorders indicate that missing pieces still remain. Gene manipulation by in utero electroporation combined with live microscopy of neural stem cells in brain slices provides a powerful method to capture their detailed behaviors during proliferation and migration. The procedures described in this chapter enable the monitoring of cell cycle progression, mitosis, morphological changes, and migratory patterns in situ. This approach facilitates the elucidation of gene functions in cortical development and neurodevelopmental disorders.
Collapse
|
36
|
Hu J, Gao X, Chen L, Kan Y, Du Z, Xin S, Ji W, Yu Q, Cao L. Identification of two rare NPRL3 variants in two Chinese families with familial focal epilepsy with variable foci 3: NGS analysis with literature review. Front Genet 2023; 13:1054567. [PMID: 36685832 PMCID: PMC9852884 DOI: 10.3389/fgene.2022.1054567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 12/19/2022] [Indexed: 01/07/2023] Open
Abstract
Background: The GAP Activity Towards Rags 1 (GATOR1) complex, which includes DEPDC5, NPRL2, and NPRL3, plays a key role in epilepsy. It has been reported that focal epilepsy is associated with mutations in the NPRL3 gene in some cases. We report two rare mutations in the NPRL3 gene in two unrelated Chinese families with focal epilepsy in this study. Methods: The proband and her brother in family E1 first experienced seizures at 1.5 and 6 years of age, respectively. Despite resection of epileptogenic foci, she still suffered recurrent seizures. The first seizure of a 20-year-old male proband in family E2 occurred when he was 2 years old. To identify pathogenic variants in these families, whole-exome sequencing (WES) was performed on genomic DNA from peripheral blood. Results: In family E1, the trio-WES analysis of the proband and her brother without apparent structural brain abnormalities identified a heterozygous variant in the NPRL3 gene (c.954C>A, p.Y318*, NM_001077350.3). In family E2, the proband carried a heterozygous NPRL3 mutation (c.1545-1G>C, NM_001077350.3). Surprisingly, the mothers of the two probands each carried the variants, but neither had an attack. Bioinformatics analysis predicted that the mutation (c.954C>A) was in the highly conserved amino acid residues of NPRL3, which affected the α-helix of NPRL3 protein, leading to a truncated protein. The splice variant (c.1545-1G>C) resulted in the loss of the last exon of the NPRL3 gene. Conclusion: The results of this study provide a foundation for diagnosing NPRL3-related epilepsy by enriching their genotypes and phenotypes and help us identify the genetic etiologies of epilepsy in these two families.
Collapse
Affiliation(s)
- Junji Hu
- Department of Neurology, Zibo Changguo Hospital, Zibo, Shandong, China
| | - Xueping Gao
- Yinfeng Gene Technology Co, Ltd, Jinan, Shandong, China
| | - Longchang Chen
- Department of Neurology, Zibo Changguo Hospital, Zibo, Shandong, China
| | - Yuling Kan
- Central Laboratory, Binzhou People’s Hospital, Binzhou, Shandong, China
| | - Zhaoli Du
- Yinfeng Gene Technology Co, Ltd, Jinan, Shandong, China
| | | | - Wenkai Ji
- Yinfeng Gene Technology Co, Ltd, Jinan, Shandong, China
| | - Qiang Yu
- Yinfeng Gene Technology Co, Ltd, Jinan, Shandong, China
| | - Lili Cao
- Department of Neurology, Cheeloo College of Medicine, Qilu Hospital, Shandong University, Jinan, China,*Correspondence: Lili Cao,
| |
Collapse
|
37
|
Iourov IY, Gerasimov AP, Zelenova MA, Ivanova NE, Kurinnaia OS, Zabrodskaya YM, Demidova IA, Barantsevich ER, Vasin KS, Kolotii AD, Ushanov VV, Sitovskaya DA, Lobzhanidze TBA, Iuditskaia ME, Iakushev NS, Zhumatov MM, Vorsanova SG, Samochernyh KA. Cytogenomic epileptology. Mol Cytogenet 2023; 16:1. [PMID: 36600272 PMCID: PMC9814426 DOI: 10.1186/s13039-022-00634-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 12/20/2022] [Indexed: 01/06/2023] Open
Abstract
Molecular cytogenetic and cytogenomic studies have made a contribution to genetics of epilepsy. However, current genomic research of this devastative condition is generally focused on the molecular genetic aspects (i.e. gene hunting, detecting mutations in known epilepsy-associated genes, searching monogenic causes of epilepsy). Nonetheless, chromosomal abnormalities and copy number variants (CNVs) represent an important part of genetic defects causing epilepsy. Moreover, somatic chromosomal mosaicism and genome/chromosome instability seem to be a possible mechanism for a wide spectrum of epileptic conditions. This idea becomes even more attracting taking into account the potential of molecular neurocytogenetic (neurocytogenomic) studies of the epileptic brain. Unfortunately, analyses of chromosome numbers and structure in the affected brain or epileptogenic brain foci are rarely performed. Therefore, one may conclude that cytogenomic area of genomic epileptology is poorly researched. Accordingly, molecular cytogenetic and cytogenomic studies of the clinical cohorts and molecular neurocytogenetic analyses of the epileptic brain appear to be required. Here, we have performed a theoretical analysis to define the targets of the aforementioned studies and to highlight future directions for molecular cytogenetic and cytogenomic research of epileptic disorders in the widest sense. To succeed, we have formed a consortium, which is planned to perform at least a part of suggested research. Taking into account the nature of the communication, "cytogenomic epileptology" has been introduced to cover the research efforts in this field of medical genomics and epileptology. Additionally, initial results of studying cytogenomic variations in the Russian neurodevelopmental cohort are reviewed with special attention to epilepsy. In total, we have concluded that (i) epilepsy-associated cytogenomic variations require more profound research; (ii) ontological analyses of epilepsy genes affected by chromosomal rearrangements and/or CNVs with unraveling pathways implicating epilepsy-associated genes are beneficial for epileptology; (iii) molecular neurocytogenetic (neurocytogenomic) analysis of postoperative samples are warranted in patients suffering from epileptic disorders.
Collapse
Affiliation(s)
- Ivan Y. Iourov
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia ,grid.445984.00000 0001 2224 0652Department of Medical Biological Disciplines, Belgorod State University, Belgorod, Russia
| | - Alexandr P. Gerasimov
- grid.452417.1Research Laboratory of Pediatric Neurosurgery, Polenov Neurosurgical Institute, Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Maria A. Zelenova
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Natalya E. Ivanova
- grid.452417.1Scientific Department of Polenov Neurosurgical Institute, Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Oksana S. Kurinnaia
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Yulia M. Zabrodskaya
- grid.452417.1Research Laboratory of Pathomorphology of the Nervous System, Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Irina A. Demidova
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Evgeny R. Barantsevich
- grid.412460.5Postgraduate Neurology and Manual Medicine Department, Pavlov First Saint-Petersburg State Medical University, Saint Petersburg, Russia
| | - Kirill S. Vasin
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Alexey D. Kolotii
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Vseslav V. Ushanov
- grid.452417.1Department of Neurosurgery, Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Darya A. Sitovskaya
- grid.452417.1Research Laboratory of Pathomorphology of the Nervous System, Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Timur B.-A. Lobzhanidze
- grid.445931.e0000 0004 0471 4078Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russia
| | - Maria E. Iuditskaia
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Nikita S. Iakushev
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Muslim M. Zhumatov
- grid.445931.e0000 0004 0471 4078Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russia
| | - Svetlana G. Vorsanova
- grid.466467.10000 0004 0627 319XYurov’s Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia ,grid.78028.350000 0000 9559 0613Vorsanova’s Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Konstantin A. Samochernyh
- grid.452417.1Polenov Neurosurgical Institute, Almazov National Medical Research Centre, Saint Petersburg, Russia
| |
Collapse
|
38
|
Kong X, Shu X, Wang J, Liu D, Ni Y, Zhao W, Wang L, Gao Z, Chen J, Yang B, Guo X, Wang Z. Fine-tuning of mTOR signaling by the UBE4B-KLHL22 E3 ubiquitin ligase cascade in brain development. Development 2022; 149:286123. [PMID: 36440598 PMCID: PMC9845739 DOI: 10.1242/dev.201286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022]
Abstract
Spatiotemporal regulation of the mechanistic target of rapamycin (mTOR) pathway is pivotal for establishment of brain architecture. Dysregulation of mTOR signaling is associated with a variety of neurodevelopmental disorders. Here, we demonstrate that the UBE4B-KLHL22 E3 ubiquitin ligase cascade regulates mTOR activity in neurodevelopment. In a mouse model with UBE4B conditionally deleted in the nervous system, animals display severe growth defects, spontaneous seizures and premature death. Loss of UBE4B in the brains of mutant mice results in depletion of neural precursor cells and impairment of neurogenesis. Mechanistically, UBE4B polyubiquitylates and degrades KLHL22, an E3 ligase previously shown to degrade the GATOR1 component DEPDC5. Deletion of UBE4B causes upregulation of KLHL22 and hyperactivation of mTOR, leading to defective proliferation and differentiation of neural precursor cells. Suppression of KLHL22 expression reverses the elevated activity of mTOR caused by acute local deletion of UBE4B. Prenatal treatment with the mTOR inhibitor rapamycin rescues neurogenesis defects in Ube4b mutant mice. Taken together, these findings demonstrate that UBE4B and KLHL22 are essential for maintenance and differentiation of the precursor pool through fine-tuning of mTOR activity.
Collapse
Affiliation(s)
- Xiangxing Kong
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Xin Shu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiachuan Wang
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining 314400, China,Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, EH8 9YL, UK
| | - Dandan Liu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yingchun Ni
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Weiqi Zhao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Lebo Wang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Zhihua Gao
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Jiadong Chen
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Bing Yang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China,Authors for correspondence (; ; )
| | - Xing Guo
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China,Authors for correspondence (; ; )
| | - Zhiping Wang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China,The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China,Authors for correspondence (; ; )
| |
Collapse
|
39
|
Focal cortical dysplasia as a cause of epilepsy: The current evidence of associated genes and future therapeutic treatments. INTERDISCIPLINARY NEUROSURGERY 2022. [DOI: 10.1016/j.inat.2022.101635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
40
|
Iffland PH, Everett ME, Cobb-Pitstick KM, Bowser LE, Barnes AE, Babus JK, Romanowski AJ, Baybis M, Elziny S, Puffenberger EG, Gonzaga-Jauregui C, Poulopoulos A, Carson VJ, Crino PB. NPRL3 loss alters neuronal morphology, mTOR localization, cortical lamination and seizure threshold. Brain 2022; 145:3872-3885. [PMID: 35136953 PMCID: PMC10200289 DOI: 10.1093/brain/awac044] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/10/2021] [Accepted: 12/10/2021] [Indexed: 08/13/2023] Open
Abstract
Mutations in nitrogen permease regulator-like 3 (NPRL3), a component of the GATOR1 complex within the mTOR pathway, are associated with epilepsy and malformations of cortical development. Little is known about the effects of NPRL3 loss on neuronal mTOR signalling and morphology, or cerebral cortical development and seizure susceptibility. We report the clinical phenotypic spectrum of a founder NPRL3 pedigree (c.349delG, p.Glu117LysFS; n = 133) among Old Order Mennonites dating to 1727. Next, as a strategy to define the role of NPRL3 in cortical development, CRISPR/Cas9 Nprl3 knockout in Neuro2a cells in vitro and in foetal mouse brain in vivo was used to assess the effects of Nprl3 knockout on mTOR activation, subcellular mTOR localization, nutrient signalling, cell morphology and aggregation, cerebral cortical cytoarchitecture and network integrity. The NPRL3 pedigree exhibited an epilepsy penetrance of 28% and heterogeneous clinical phenotypes with a range of epilepsy semiologies, i.e. focal or generalized onset, brain imaging abnormalities, i.e. polymicrogyria, focal cortical dysplasia or normal imaging, and EEG findings, e.g. focal, multi-focal or generalized spikes, focal or generalized slowing. Whole exome analysis comparing a seizure-free group (n = 37) to those with epilepsy (n = 24) to search for gene modifiers for epilepsy did not identify a unique genetic modifier that explained the variability in seizure penetrance in this cohort. Nprl3 knockout in vitro caused mTOR pathway hyperactivation, cell soma enlargement and the formation of cellular aggregates seen in time-lapse videos that were prevented with the mTOR inhibitors rapamycin or torin1. In Nprl3 knockout cells, mTOR remained localized on the lysosome in a constitutively active conformation, as evidenced by phosphorylation of ribosomal S6 and 4E-BP1 proteins, even under nutrient starvation (amino acid-free) conditions, demonstrating that Nprl3 loss decouples mTOR activation from neuronal metabolic state. To model human malformations of cortical development associated with NPRL3 variants, we created a focal Nprl3 knockout in foetal mouse cortex by in utero electroporation and found altered cortical lamination and white matter heterotopic neurons, effects which were prevented with rapamycin treatment. EEG recordings showed network hyperexcitability and reduced seizure threshold to pentylenetetrazol treatment. NPRL3 variants are linked to a highly variable clinical phenotype which we propose results from mTOR-dependent effects on cell structure, cortical development and network organization.
Collapse
Affiliation(s)
- Philip H Iffland
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| | | | | | | | - Allan E Barnes
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| | - Janice K Babus
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| | - Andrea J Romanowski
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| | - Marianna Baybis
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| | - Soad Elziny
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| | | | | | - Alexandros Poulopoulos
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| | | | - Peter B Crino
- University of Maryland School of Medicine Departments of Neurology and Pharmacology, Baltimore, MD 21201, USA
| |
Collapse
|
41
|
Xu Y, Zhao R, Wang M, Wang X, Wang Y, Li H, Ma Y, Wu B, Zhou Y. Identification of genetic characteristics in pediatric epilepsy with focal cortical dysplasia type 2 using deep whole-exome sequencing. Mol Genet Genomic Med 2022; 10:e2086. [PMID: 36342087 PMCID: PMC9747558 DOI: 10.1002/mgg3.2086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/26/2022] [Accepted: 10/21/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Focal cortical dysplasia type 2 (FCD2) is a malformation of cortical development that constitutes a common cause of pediatric focal epilepsy. Germline or somatic variants in the mammalian target of rapamycin (mTOR) signaling pathway genes are the pathogenesis of FCD2. OBJECTIVE In this study, whole-exome deep sequencing was performed on dysplastic cortex from focal epilepsy in children to explore genetic characteristics in FCD2. METHODS Resected core lesions of FCD2 were confirmed by pathology, and peripheral blood was collected from 11 patients. Deep whole-exome sequencing (>500X) was performed on derived genomic DNA, germline, or somatic variants in brain-specific genes were analyzed and identified. RESULTS In 11 patients, a heterozygous likely pathogenic germline variant of DEPDC5 was identified in one case, while somatic variants were found in four brain samples. The frequencies of the somatic variant allele were 2.52%-5.12%. Somatic variants in AKT3, TSC2, and MTOR (mTOR signaling pathway genes) were found in three samples. Besides, one somatic variant was detected in MED12 which has not been reported to associate with FCD2. CONCLUSION Our study expanded the variant spectrum in the mTOR-GATOR pathway, and also detected a somatic variant in MED12 which was potentially associated with FCD 2.
Collapse
Affiliation(s)
- Yan Xu
- Department of Neurology and Epilepsy CenterChildren's Hospital of Fudan UniversityShanghaiChina
| | - Rui Zhao
- Department of NeurosurgeryChildren's Hospital of Fudan UniversityShanghaiChina
| | - Min Wang
- Department of NeurosurgeryChildren's Hospital of Fudan UniversityShanghaiChina
| | - Xin‐hua Wang
- Department of Neurology and Epilepsy CenterChildren's Hospital of Fudan UniversityShanghaiChina
| | - Yi Wang
- Department of Neurology and Epilepsy CenterChildren's Hospital of Fudan UniversityShanghaiChina
| | - Hao Li
- Department of NeurosurgeryChildren's Hospital of Fudan UniversityShanghaiChina
| | - Yang‐yang Ma
- Department of PathologyChildren's Hospital of Fudan UniversityShanghaiChina
| | - Bing‐bing Wu
- Center for Molecular MedicinePediatrics Research Institute, Children's Hospital of Fudan UniversityShanghaiChina
| | - Yuan‐feng Zhou
- Department of Neurology and Epilepsy CenterChildren's Hospital of Fudan UniversityShanghaiChina
| |
Collapse
|
42
|
Iourov IY, Vorsanova SG, Kurinnaia OS, Kutsev SI, Yurov YB. Somatic mosaicism in the diseased brain. Mol Cytogenet 2022; 15:45. [PMID: 36266706 PMCID: PMC9585840 DOI: 10.1186/s13039-022-00624-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/10/2022] Open
Abstract
It is hard to believe that all the cells of a human brain share identical genomes. Indeed, single cell genetic studies have demonstrated intercellular genomic variability in the normal and diseased brain. Moreover, there is a growing amount of evidence on the contribution of somatic mosaicism (the presence of genetically different cell populations in the same individual/tissue) to the etiology of brain diseases. However, brain-specific genomic variations are generally overlooked during the research of genetic defects associated with a brain disease. Accordingly, a review of brain-specific somatic mosaicism in disease context seems to be required. Here, we overview gene mutations, copy number variations and chromosome abnormalities (aneuploidy, deletions, duplications and supernumerary rearranged chromosomes) detected in the neural/neuronal cells of the diseased brain. Additionally, chromosome instability in non-cancerous brain diseases is addressed. Finally, theoretical analysis of possible mechanisms for neurodevelopmental and neurodegenerative disorders indicates that a genetic background for formation of somatic (chromosomal) mosaicism in the brain is likely to exist. In total, somatic mosaicism affecting the central nervous system seems to be a mechanism of brain diseases.
Collapse
Affiliation(s)
- Ivan Y Iourov
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia. .,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia. .,Department of Medical Biological Disciplines, Belgorod State University, Belgorod, Russia.
| | - Svetlana G Vorsanova
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia.,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | - Oxana S Kurinnaia
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia.,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| | | | - Yuri B Yurov
- Yurov's Laboratory of Molecular Genetics and Cytogenomics of the Brain, Mental Health Research Center, Moscow, Russia.,Vorsanova's Laboratory of Molecular Cytogenetics of Neuropsychiatric Diseases, Veltischev Research and Clinical Institute for Pediatrics and Pediatric Surgery of the Pirogov Russian National Research Medical University of the Russian Ministry of Health, Moscow, Russia
| |
Collapse
|
43
|
De Meulemeester AS, Heylen L, Siekierska A, Mills JD, Romagnolo A, Van Der Wel NN, Aronica E, de Witte PAM. Hyperactivation of mTORC1 in a double hit mutant zebrafish model of tuberous sclerosis complex causes increased seizure susceptibility and neurodevelopmental abnormalities. Front Cell Dev Biol 2022; 10:952832. [PMID: 36238691 PMCID: PMC9552079 DOI: 10.3389/fcell.2022.952832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is a multisystem genetic disorder caused by pathogenic variants in TSC1 and TSC2 genes. TSC patients present with seizures and brain abnormalities such as tubers and subependymal giant cells astrocytoma (SEGA). Despite common molecular and clinical features, the severity of the disease varies greatly, even intrafamilially. The second hit hypothesis suggests that an additional, inactivating mutation in the remaining functional allele causes a more severe phenotype and therefore explains the phenotypic variability. Recently, second hit mutations have been detected frequently in mTORopathies. To investigate the pathophysiological effects of second hit mutations, several mouse models have been developed. Here, we opted for a double mutant zebrafish model that carries a LOF mutation both in the tsc2 and the depdc5 gene. To the best of our knowledge, this is the first time a second-hit model has been studied in zebrafish. Significantly, the DEP domain-containing protein 5 (DEPDC5) gene has an important role in the regulation of mTORC1, and the combination of a germline TSC2 and somatic DEPDC5 mutation has been described in a TSC patient with intractable epilepsy. Our depdc5−/−x tsc2−/− double mutant zebrafish line displayed greatly increased levels of mammalian target of rapamycin (mTORC1) activity, augmented seizure susceptibility, and early lethality which could be rescued by rapamycin. Histological analysis of the brain revealed ventricular dilatation in the tsc2 and double homozygotes. RNA-sequencing showed a linear relation between the number of differentially expressed genes (DEGs) and the degree of mTORC1 hyperactivity. Enrichment analysis of their transcriptomes revealed that many genes associated with neurological developmental processes were downregulated and mitochondrial genes were upregulated. In particular, the transcriptome of human SEGA lesions overlapped strongly with the double homozygous zebrafish larvae. The data highlight the clinical relevance of the depdc5−/− x tsc2−/− double mutant zebrafish larvae that showed a more severe phenotype compared to the single mutants. Finally, analysis of gene-drug interactions identified interesting pharmacological targets for SEGA, underscoring the value of our small zebrafish vertebrate model for future drug discovery efforts.
Collapse
Affiliation(s)
| | - Lise Heylen
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
| | | | - James D. Mills
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
- Chalfont Centre for Epilepsy, Chalfont St Peter, United Kingdom
| | - Alessia Romagnolo
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
| | - Nicole N. Van Der Wel
- Department of Medical Biology, Electron Microscopy Center Amsterdam, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology Amsterdam Neuroscience, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instelling Nederland (SEIN), Heemstede, Netherlands
| | - Peter A. M. de Witte
- Laboratory for Molecular Biodiscovery, KU Leuven, Leuven, Belgium
- *Correspondence: Peter A. M. de Witte,
| |
Collapse
|
44
|
Ververi A, Zagaglia S, Menzies L, Baptista J, Caswell R, Baulac S, Ellard S, Lynch S, Jacques TS, Chawla MS, Heier M, Kulseth MA, Mero IL, Våtevik AK, Kraoua I, Ben Rhouma H, Ben Younes T, Miladi Z, Ben Youssef Turki I, Jones WD, Clement E, Eltze C, Mankad K, Merve A, Parker J, Hoskins B, Pressler R, Sudhakar S, DeVile C, Homfray T, Kaliakatsos M, Robinson R, Keim SMB, Habibi I, Reymond A, Sisodiya SM, Hurst JA. Germline homozygous missense DEPDC5 variants cause severe refractory early-onset epilepsy, macrocephaly and bilateral polymicrogyria. Hum Mol Genet 2022; 32:580-594. [PMID: 36067010 PMCID: PMC9896472 DOI: 10.1093/hmg/ddac225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 08/16/2022] [Accepted: 08/31/2022] [Indexed: 02/07/2023] Open
Abstract
DEPDC5 (DEP Domain-Containing Protein 5) encodes an inhibitory component of the mammalian target of rapamycin (mTOR) pathway and is commonly implicated in sporadic and familial focal epilepsies, both non-lesional and in association with focal cortical dysplasia. Germline pathogenic variants are typically heterozygous and inactivating. We describe a novel phenotype caused by germline biallelic missense variants in DEPDC5. Cases were identified clinically. Available records, including magnetic resonance imaging and electroencephalography, were reviewed. Genetic testing was performed by whole exome and whole-genome sequencing and cascade screening. In addition, immunohistochemistry was performed on skin biopsy. The phenotype was identified in nine children, eight of which are described in detail herein. Six of the children were of Irish Traveller, two of Tunisian and one of Lebanese origin. The Irish Traveller children shared the same DEPDC5 germline homozygous missense variant (p.Thr337Arg), whereas the Lebanese and Tunisian children shared a different germline homozygous variant (p.Arg806Cys). Consistent phenotypic features included extensive bilateral polymicrogyria, congenital macrocephaly and early-onset refractory epilepsy, in keeping with other mTOR-opathies. Eye and cardiac involvement and severe neutropenia were also observed in one or more patients. Five of the children died in infancy or childhood; the other four are currently aged between 5 months and 6 years. Skin biopsy immunohistochemistry was supportive of hyperactivation of the mTOR pathway. The clinical, histopathological and genetic evidence supports a causal role for the homozygous DEPDC5 variants, expanding our understanding of the biology of this gene.
Collapse
Affiliation(s)
| | | | | | | | - Richard Caswell
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Stephanie Baulac
- Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Sorbonne Université, F-75013 Paris, France
| | - Sian Ellard
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Sally Lynch
- Academic Centre on Rare Diseases, University College Dublin School of Medicine and Medical Science, Dublin, Ireland,Department of Clinical Genetics, Children's Health Ireland (CHI) at Crumlin, Dublin, Ireland
| | | | - Thomas S Jacques
- Developmental Biology and Cancer Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK,Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | - Martin Heier
- Department of Clinical Neuroscience for Children, Oslo University Hospital, Oslo, Norway
| | - Mari Ann Kulseth
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Inger-Lise Mero
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | | | - Ichraf Kraoua
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Hanene Ben Rhouma
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Thouraya Ben Younes
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Zouhour Miladi
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Ilhem Ben Youssef Turki
- Research Laboratory LR18SP04, Department of Child and Adolescent Neurology, National Institute Mongi Ben Hmida of Neurology, Tunis, Tunisia. Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Wendy D Jones
- Department of Clinical Genetics & Genomic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Emma Clement
- Department of Clinical Genetics & Genomic Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Christin Eltze
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Kshitij Mankad
- Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Ashirwad Merve
- Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Jennifer Parker
- North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Bethan Hoskins
- North Thames Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Ronit Pressler
- Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Sniya Sudhakar
- Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Catherine DeVile
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Tessa Homfray
- SW Thames Regional Genetics Service, St George's Hospital, St George's University of London, London, UK
| | - Marios Kaliakatsos
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Ponnudas (Prab) Prabhakar
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Robert Robinson
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | - Imen Habibi
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Alexandre Reymond
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Sanjay M Sisodiya
- To whom correspondence should be addressed at: Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK.
| | | |
Collapse
|
45
|
Lai D, Gade M, Yang E, Koh HY, Lu J, Walley NM, Buckley AF, Sands TT, Akman CI, Mikati MA, McKhann GM, Goldman JE, Canoll P, Alexander AL, Park KL, Von Allmen GK, Rodziyevska O, Bhattacharjee MB, Lidov HGW, Vogel H, Grant GA, Porter BE, Poduri AH, Crino PB, Heinzen EL. Somatic variants in diverse genes leads to a spectrum of focal cortical malformations. Brain 2022; 145:2704-2720. [PMID: 35441233 PMCID: PMC9612793 DOI: 10.1093/brain/awac117] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/19/2022] [Accepted: 03/13/2022] [Indexed: 11/14/2022] Open
Abstract
Post-zygotically acquired genetic variants, or somatic variants, that arise during cortical development have emerged as important causes of focal epilepsies, particularly those due to malformations of cortical development. Pathogenic somatic variants have been identified in many genes within the PI3K-AKT-mTOR-signalling pathway in individuals with hemimegalencephaly and focal cortical dysplasia (type II), and more recently in SLC35A2 in individuals with focal cortical dysplasia (type I) or non-dysplastic epileptic cortex. Given the expanding role of somatic variants across different brain malformations, we sought to delineate the landscape of somatic variants in a large cohort of patients who underwent epilepsy surgery with hemimegalencephaly or focal cortical dysplasia. We evaluated samples from 123 children with hemimegalencephaly (n = 16), focal cortical dysplasia type I and related phenotypes (n = 48), focal cortical dysplasia type II (n = 44), or focal cortical dysplasia type III (n = 15). We performed high-depth exome sequencing in brain tissue-derived DNA from each case and identified somatic single nucleotide, indel and large copy number variants. In 75% of individuals with hemimegalencephaly and 29% with focal cortical dysplasia type II, we identified pathogenic variants in PI3K-AKT-mTOR pathway genes. Four of 48 cases with focal cortical dysplasia type I (8%) had a likely pathogenic variant in SLC35A2. While no other gene had multiple disease-causing somatic variants across the focal cortical dysplasia type I cohort, four individuals in this group had a single pathogenic or likely pathogenic somatic variant in CASK, KRAS, NF1 and NIPBL, genes previously associated with neurodevelopmental disorders. No rare pathogenic or likely pathogenic somatic variants in any neurological disease genes like those identified in the focal cortical dysplasia type I cohort were found in 63 neurologically normal controls (P = 0.017), suggesting a role for these novel variants. We also identified a somatic loss-of-function variant in the known epilepsy gene, PCDH19, present in a small number of alleles in the dysplastic tissue from a female patient with focal cortical dysplasia IIIa with hippocampal sclerosis. In contrast to focal cortical dysplasia type II, neither focal cortical dysplasia type I nor III had somatic variants in genes that converge on a unifying biological pathway, suggesting greater genetic heterogeneity compared to type II. Importantly, we demonstrate that focal cortical dysplasia types I, II and III are associated with somatic gene variants across a broad range of genes, many associated with epilepsy in clinical syndromes caused by germline variants, as well as including some not previously associated with radiographically evident cortical brain malformations.
Collapse
Affiliation(s)
- Dulcie Lai
- Division of Pharmacology and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Meethila Gade
- Division of Pharmacology and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Edward Yang
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hyun Yong Koh
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA.,Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Jinfeng Lu
- Division of Pharmacology and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nicole M Walley
- Division of Medical Genetics, Department of Pediatrics, Duke University School of Medicine, Durham, NC 27710, USA
| | - Anne F Buckley
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
| | - Tristan T Sands
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY 10032, USA.,Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - Cigdem I Akman
- Department of Neurology, Columbia University Medical Center, New York, NY 10032, USA
| | - Mohamad A Mikati
- Department of Neurobiology, Duke University, Durham, NC 27708, USA.,Division of Pediatric Neurology, Duke University Medical Center, Durham, NC 27710, USA
| | - Guy M McKhann
- Department of Neurosurgery, Columbia University, New York Presbyterian Hospital, New York, NY 10032, USA
| | - James E Goldman
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Peter Canoll
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Allyson L Alexander
- Department of Neurosurgery, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kristen L Park
- Department of Pediatrics and Neurology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Gretchen K Von Allmen
- Department of Neurology, McGovern Medical School, Houston, TX 77030, USA.,Division of Child Neurology, Department of Pediatrics, McGovern Medical School, Houston, TX 77030, USA
| | - Olga Rodziyevska
- Division of Child Neurology, Department of Pediatrics, McGovern Medical School, Houston, TX 77030, USA
| | | | - Hart G W Lidov
- Department of Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Gerald A Grant
- Department of Neurosurgery, Lucile Packard Children's Hospital at Stanford, School of Medicine, Stanford, CA 94305, USA
| | - Brenda E Porter
- Department of Neurology and Neurological Sciences, Stanford University, School of Medicine, Stanford, CA 94305, USA
| | - Annapurna H Poduri
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA.,Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Erin L Heinzen
- Division of Pharmacology and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| |
Collapse
|
46
|
Najm I, Lal D, Alonso Vanegas M, Cendes F, Lopes-Cendes I, Palmini A, Paglioli E, Sarnat HB, Walsh CA, Wiebe S, Aronica E, Baulac S, Coras R, Kobow K, Cross JH, Garbelli R, Holthausen H, Rössler K, Thom M, El-Osta A, Lee JH, Miyata H, Guerrini R, Piao YS, Zhou D, Blümcke I. The ILAE consensus classification of focal cortical dysplasia: An update proposed by an ad hoc task force of the ILAE diagnostic methods commission. Epilepsia 2022; 63:1899-1919. [PMID: 35706131 PMCID: PMC9545778 DOI: 10.1111/epi.17301] [Citation(s) in RCA: 100] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/24/2022] [Accepted: 05/13/2022] [Indexed: 02/05/2023]
Abstract
Ongoing challenges in diagnosing focal cortical dysplasia (FCD) mandate continuous research and consensus agreement to improve disease definition and classification. An International League Against Epilepsy (ILAE) Task Force (TF) reviewed the FCD classification of 2011 to identify existing gaps and provide a timely update. The following methodology was applied to achieve this goal: a survey of published literature indexed with ((Focal Cortical Dysplasia) AND (epilepsy)) between 01/01/2012 and 06/30/2021 (n = 1349) in PubMed identified the knowledge gained since 2012 and new developments in the field. An online survey consulted the ILAE community about the current use of the FCD classification scheme with 367 people answering. The TF performed an iterative clinico-pathological and genetic agreement study to objectively measure the diagnostic gap in blood/brain samples from 22 patients suspicious for FCD and submitted to epilepsy surgery. The literature confirmed new molecular-genetic characterizations involving the mechanistic Target Of Rapamycin (mTOR) pathway in FCD type II (FCDII), and SLC35A2 in mild malformations of cortical development (mMCDs) with oligodendroglial hyperplasia (MOGHE). The electro-clinical-imaging phenotypes and surgical outcomes were better defined and validated for FCDII. Little new information was acquired on clinical, histopathological, or genetic characteristics of FCD type I (FCDI) and FCD type III (FCDIII). The survey identified mMCDs, FCDI, and genetic characterization as fields for improvement in an updated classification. Our iterative clinico-pathological and genetic agreement study confirmed the importance of immunohistochemical staining, neuroimaging, and genetic tests to improve the diagnostic yield. The TF proposes to include mMCDs, MOGHE, and "no definite FCD on histopathology" as new categories in the updated FCD classification. The histopathological classification can be further augmented by advanced neuroimaging and genetic studies to comprehensively diagnose FCD subtypes; these different levels should then be integrated into a multi-layered diagnostic scheme. This update may help to foster multidisciplinary efforts toward a better understanding of FCD and the development of novel targeted treatment options.
Collapse
Affiliation(s)
- Imad Najm
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland, Ohio, USA
| | - Dennis Lal
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland, Ohio, USA.,Genomic Medicine Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Fernando Cendes
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil.,Department of Neurology, University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
| | - Iscia Lopes-Cendes
- Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil.,Department of Translational Medicine, University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
| | - Andre Palmini
- Department of Clinical Neurosciences, School of Medicine, Pontificia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.,Porto Alegre Epilepsy Surgery Program, Hospital São Lucas PUCRS, Porto Alegre, Brazil
| | - Eliseu Paglioli
- Department of Surgery, School of Medicine, Pontificia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Harvey B Sarnat
- Department of Paediatrics, Department of Pathology (Neuropathology) and Department of Clinical Neurosciences, University of Calgary Faculty of Medicine, Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada
| | - Christopher A Walsh
- Division of Genetics and Genomics and Howard Hughes Medical Institute, Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA.,Departments of Pediatrics and Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Samuel Wiebe
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Eleonora Aronica
- Department of (Neuro) Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, the Netherlands
| | - Stéphanie Baulac
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Roland Coras
- Department of Neuropathology, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Katja Kobow
- Developmental Neurosciences Programme, UCL NIHR BRC Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - J Helen Cross
- Developmental Neurosciences Programme, UCL NIHR BRC Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Rita Garbelli
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Hans Holthausen
- Center for Pediatric Neurology, Neurorehabilitation and Epileptology, Schoen-Clinic, Vogtareuth, Germany
| | - Karl Rössler
- Department of Neurosurgery, Allgemeines Krankenhaus Wien, Vienna Medical University, Wien, Austria
| | - Maria Thom
- Department of Neuropathology, Institute of Neurology, University College London, UK
| | - Assam El-Osta
- Epigenetics in Human Health and Disease Laboratory, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Jeong Ho Lee
- Graduate School of Medical Science and Engineering, KAIST and SoVarGen, Daejeon, South Korea
| | - Hajime Miyata
- Department of Neuropathology, Research Institute for Brain and Blood Vessels, Akita Cerebrospinal and Cardiovascular Center, Akita, Japan
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Anna Meyer- University of Florence, Florence, Italy
| | - Yue-Shan Piao
- National Center for Neurological Disorders, Department of Pathology, Xuanwu Hospital, Capital Medical University, and Clinical Research Center for Epilepsy, Capital Medical University, Beijing, China
| | - Dong Zhou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Ingmar Blümcke
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland, Ohio, USA.,Department of Neuropathology, Universitätsklinikum Erlangen, Erlangen, Germany
| |
Collapse
|
47
|
Green TE, Motelow JE, Bennett MF, Ye Z, Bennett CA, Griffin NG, Damiano JA, Leventer RJ, Freeman JL, Harvey AS, Lockhart PJ, Sadleir LG, Boys A, Scheffer IE, Major H, Darbro BW, Bahlo M, Goldstein DB, Kerrigan JF, Heinzen EL, Berkovic SF, Hildebrand MS. Sporadic hypothalamic hamartoma is a ciliopathy with somatic and bi-allelic contributions. Hum Mol Genet 2022; 31:2307-2316. [PMID: 35137044 PMCID: PMC9307310 DOI: 10.1093/hmg/ddab366] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/02/2021] [Accepted: 12/15/2021] [Indexed: 11/13/2022] Open
Abstract
Hypothalamic hamartoma with gelastic seizures is a well-established cause of drug-resistant epilepsy in early life. The development of novel surgical techniques has permitted the genomic interrogation of hypothalamic hamartoma tissue. This has revealed causative mosaic variants within GLI3, OFD1 and other key regulators of the sonic-hedgehog pathway in a minority of cases. Sonic-hedgehog signalling proteins localize to the cellular organelle primary cilia. We therefore explored the hypothesis that cilia gene variants may underlie hitherto unsolved cases of sporadic hypothalamic hamartoma. We performed high-depth exome sequencing and chromosomal microarray on surgically resected hypothalamic hamartoma tissue and paired leukocyte-derived DNA from 27 patients. We searched for both germline and somatic variants under both dominant and bi-allelic genetic models. In hamartoma-derived DNA of seven patients we identified bi-allelic (one germline, one somatic) variants within one of four cilia genes-DYNC2I1, DYNC2H1, IFT140 or SMO. In eight patients, we identified single somatic variants in the previously established hypothalamic hamartoma disease genes GLI3 or OFD1. Overall, we established a plausible molecular cause for 15/27 (56%) patients. Here, we expand the genetic architecture beyond single variants within dominant disease genes that cause sporadic hypothalamic hamartoma to bi-allelic (one germline/one somatic) variants, implicate three novel cilia genes and reconceptualize the disorder as a ciliopathy.
Collapse
Affiliation(s)
- Timothy E Green
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Joshua E Motelow
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - Mark F Bennett
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Zimeng Ye
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Caitlin A Bennett
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Nicole G Griffin
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
| | - John A Damiano
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Richard J Leventer
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - Jeremy L Freeman
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - A Simon Harvey
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - Paul J Lockhart
- Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| | - Lynette G Sadleir
- Department of Paediatrics and Child Health, University of Otago, Wellington 6242, New Zealand
| | - Amber Boys
- Victorian Clinical Genetics Services, Parkville, VIC 3052, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
- Department of Neurology, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Heather Major
- Department of Pediatrics, The University of Iowa, Iowa City, IA 52246, USA
| | - Benjamin W Darbro
- Department of Pediatrics, The University of Iowa, Iowa City, IA 52246, USA
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria 3052, Australia
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University, New York, NY 10032, USA
- Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - John F Kerrigan
- Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ 85013, USA
| | - Erin L Heinzen
- Eshelman School of Pharmacy, Division of Pharmacotherapy and Experimental Therapeutics, and Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, VIC 3084, Australia
- Murdoch Children’s Research Institute, The Royal Children’s Hospital, Parkville, VIC 3052, Australia
| |
Collapse
|
48
|
Bedrosian TA, Miller KE, Grischow OE, Schieffer KM, LaHaye S, Yoon H, Miller AR, Navarro J, Westfall J, Leraas K, Choi S, Williamson R, Fitch J, Kelly BJ, White P, Lee K, McGrath S, Cottrell CE, Magrini V, Leonard J, Pindrik J, Shaikhouni A, Boué DR, Thomas DL, Pierson CR, Wilson RK, Ostendorf AP, Mardis ER, Koboldt DC. Detection of brain somatic variation in epilepsy-associated developmental lesions. Epilepsia 2022; 63:1981-1997. [PMID: 35687047 DOI: 10.1111/epi.17323] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/07/2022] [Accepted: 06/07/2022] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Epilepsy-associated developmental lesions, including malformations of cortical development and low-grade developmental tumors, represent a major cause of drug-resistant seizures requiring surgical intervention in children. Brain-restricted somatic mosaicism has been implicated in the genetic etiology of these lesions; however, many contributory genes remain unidentified. METHODS We enrolled 50 children who were undergoing epilepsy surgery into a translational research study. Resected tissue was divided for clinical neuropathologic evaluation and genomic analysis. We performed exome and RNA sequencing to identify somatic variation and we confirmed our findings using high-depth targeted DNA sequencing. RESULTS We uncovered candidate disease-causing somatic variation affecting 28 patients (56%), as well as candidate germline variants affecting 4 patients (8%). In agreement with previous studies, we identified somatic variation affecting solute carrier family 35 member A2 (SLC35A2) and mechanistic target of rapamycin kinase (MTOR) pathway genes in patients with focal cortical dysplasia. Somatic gains of chromosome 1q were detected in 30% (3 of 10) of patients with Type I focal cortical dysplasia (FCD)s. Somatic variation in mitogen-activated protein kinase (MAPK) pathway genes (i.e., fibroblast growth factor receptor 1 [FGFR1], FGFR2, B-raf proto-oncogene, serine/threonine kinase [BRAF], and KRAS proto-oncogene, GTPase [KRAS]) was associated with low-grade epilepsy-associated developmental tumors. RNA sequencing enabled the detection of somatic structural variation that would have otherwise been missed, and which accounted for more than one-half of epilepsy-associated tumor diagnoses. Sampling across multiple anatomic regions revealed that somatic variant allele fractions vary widely within epileptogenic tissue. Finally, we identified putative disease-causing variants in genes not yet associated with focal cortical dysplasia. SIGNIFICANCE These results further elucidate the genetic basis of structural brain abnormalities leading to focal epilepsy in children and point to new candidate disease genes.
Collapse
Affiliation(s)
- Tracy A Bedrosian
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Katherine E Miller
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Olivia E Grischow
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Kathleen M Schieffer
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Stephanie LaHaye
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Hyojung Yoon
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Anthony R Miller
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Jason Navarro
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Jesse Westfall
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Kristen Leraas
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Samantha Choi
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Rachel Williamson
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - James Fitch
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Benjamin J Kelly
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Peter White
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Kristy Lee
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Sean McGrath
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Catherine E Cottrell
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Vincent Magrini
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Jeffrey Leonard
- Department of Neurosurgery, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Neurosurgery, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Jonathan Pindrik
- Department of Neurosurgery, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Neurosurgery, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Ammar Shaikhouni
- Department of Neurosurgery, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Neurosurgery, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Daniel R Boué
- Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Division of Anatomy, Department of Biomedical Education & Anatomy, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Diana L Thomas
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Christopher R Pierson
- Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Division of Anatomy, Department of Biomedical Education & Anatomy, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Richard K Wilson
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Adam P Ostendorf
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Division of Pediatric Neurology, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Elaine R Mardis
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Neurosurgery, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Daniel C Koboldt
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| |
Collapse
|
49
|
Wang G, Wu W, Xu Y, Yang Z, Xiao B, Long L. Imaging Genetics in Epilepsy: Current Knowledge and New Perspectives. Front Mol Neurosci 2022; 15:891621. [PMID: 35706428 PMCID: PMC9189397 DOI: 10.3389/fnmol.2022.891621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/06/2022] [Indexed: 12/11/2022] Open
Abstract
Epilepsy is a neurological network disease with genetics playing a much greater role than was previously appreciated. Unfortunately, the relationship between genetic basis and imaging phenotype is by no means simple. Imaging genetics integrates multidimensional datasets within a unified framework, providing a unique opportunity to pursue a global vision for epilepsy. This review delineates the current knowledge of underlying genetic mechanisms for brain networks in different epilepsy syndromes, particularly from a neural developmental perspective. Further, endophenotypes and their potential value are discussed. Finally, we highlight current challenges and provide perspectives for the future development of imaging genetics in epilepsy.
Collapse
Affiliation(s)
- Ge Wang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Wenyue Wu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- Department of Neurology, The Second Affiliated Hospital of Nanchang University, Jiangxi, China
| | - Yuchen Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhuanyi Yang
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
| | - Lili Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, China
- *Correspondence: Lili Long
| |
Collapse
|
50
|
Dentel B, Angeles-Perez L, Ren C, Jakkamsetti V, Holley AJ, Caballero D, Oh E, Gibson J, Pascual JM, Huber KM, Tu BP, Tsai PT. Increased glycine contributes to synaptic dysfunction and early mortality in Nprl2 seizure model. iScience 2022; 25:104334. [PMID: 35602938 PMCID: PMC9118754 DOI: 10.1016/j.isci.2022.104334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 09/16/2021] [Accepted: 04/26/2022] [Indexed: 10/25/2022] Open
Abstract
Targeted therapies for epilepsies associated with the mTORC1 signaling negative regulator GATOR1 are lacking. NPRL2 is a subunit of the GATOR1 complex and mutations in GATOR1 subunits, including NPRL2, are associated with epilepsy. To delineate the mechanisms underlying NPRL2-related epilepsies, we created a mouse (Mus musculus) model with neocortical loss of Nprl2. Mutant mice have increased mTORC1 signaling and exhibit spontaneous seizures. They also display abnormal synaptic function characterized by increased evoked and spontaneous EPSC and decreased evoked and spontaneous IPSC frequencies, respectively. Proteomic and metabolomics studies of Nprl2 mutants revealed alterations in known epilepsy-implicated proteins and metabolic pathways, including increases in the neurotransmitter, glycine. Furthermore, glycine actions on the NMDA receptor contribute to the electrophysiological and survival phenotypes of these mice. Taken together, in this neuronal Nprl2 model, we delineate underlying molecular, metabolic, and electrophysiological mechanisms contributing to mTORC1-related epilepsy, providing potential therapeutic targets for epilepsy.
Collapse
Affiliation(s)
- Brianne Dentel
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | | | - Chongyu Ren
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Vikram Jakkamsetti
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Andrew J. Holley
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Daniel Caballero
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Emily Oh
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Jay Gibson
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Juan M. Pascual
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Kimberly M. Huber
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Benjamin P. Tu
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX 75235, USA
| | - Peter T. Tsai
- Department of Neurology, UT Southwestern Medical Center, Dallas, TX 75235, USA
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75235, USA
- Departments of Pediatrics and Psychiatry, UT Southwestern Medical Center, Dallas, TX 75235, USA
| |
Collapse
|