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Gu C, Wei X, Yan D, Cai Y, Li D, Shu J, Cai C. DEPDC5 plays a vital role in epilepsy: Genotypic and phenotypic features in cohort and literature. Epileptic Disord 2024; 26:341-349. [PMID: 38752894 DOI: 10.1002/epd2.20223] [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: 12/27/2023] [Revised: 03/18/2024] [Accepted: 03/24/2024] [Indexed: 06/12/2024]
Abstract
OBJECTIVE DEPDC5 emerges to play a vital role in focal epilepsy. However, genotype-phenotype correlation in DEPDC5-related focal epilepsies is challenging and controversial. In this study, we aim to investigate the genotypic and phenotypic features in DEPDC5-affected patients. METHODS Genetic testing combined with criteria published by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP), was used to identify pathogenic/likely pathogenic variants in DEPDC5 among the cohort of 479 patients with focal epilepsy. Besides, the literature review was performed to explore the genotype-phenotype correlation and the penetrance in DEPDC5-related focal epilepsies. RESULTS Eight unrelated probands were revealed to carry different pathogenic/likely pathogenic variants in DEPDC5 and the total prevalence of DEPDC5-related focal epilepsy was 1.67% in the cohort. Sixty-five variants from 28 studies were included in our review. Combined with the cases reported, null variants accounted for a larger proportion than missense variants and were related to unfavorable prognosis (drug resistance or even sudden unexpected death in epilepsy; χ2 = 5.429, p = .020). And, the prognosis of probands with developmental delay/intellectual disability or focal cortical dysplasia was worse than that of probands with simple epilepsy (χ2 = -, p = .006). Besides, the overall penetrance of variants in DEPDC5 was 68.96% (231/335). SIGNIFICANCE The study expands the variant spectrum of DEPDC5 and proves that the DEPDC5 variant plays a significant role in focal epilepsy. Due to the characteristics of phenotypic heterogeneity and incomplete penetrance, genetic testing is necessary despite no specific family history. And we propose to adopt the ACMG/AMP criteria refined by ClinGen Sequence Variant Interpretation Working Group, for consistency in usage and transparency in classification rationale. Moreover, we reveal an important message to clinicians that the prognosis of DEPDC5-affected patients is related to the variant type and complications.
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Affiliation(s)
- Chunyu Gu
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Xinping Wei
- The Medical Department of Neurology, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Dandan Yan
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Yingzi Cai
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Dong Li
- The Medical Department of Neurology, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Jianbo Shu
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Chunquan Cai
- Tianjin Pediatric Research Institute, Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
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Macdonald-Laurs E, Warren AEL, Francis P, Mandelstam SA, Lee WS, Coleman M, Stephenson SEM, Barton S, D'Arcy C, Lockhart PJ, Leventer RJ, Harvey AS. The clinical, imaging, pathological and genetic landscape of bottom-of-sulcus dysplasia. Brain 2024; 147:1264-1277. [PMID: 37939785 DOI: 10.1093/brain/awad379] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 09/20/2023] [Accepted: 10/22/2023] [Indexed: 11/10/2023] Open
Abstract
Bottom-of-sulcus dysplasia (BOSD) is increasingly recognized as a cause of drug-resistant, surgically-remediable, focal epilepsy, often in seemingly MRI-negative patients. We describe the clinical manifestations, morphological features, localization patterns and genetics of BOSD, with the aims of improving management and understanding pathogenesis. We studied 85 patients with BOSD diagnosed between 2005-2022. Presenting seizure and EEG characteristics, clinical course, genetic findings and treatment response were obtained from medical records. MRI (3 T) and 18F-FDG-PET scans were reviewed systematically for BOSD morphology and metabolism. Histopathological analysis and tissue genetic testing were performed in 64 operated patients. BOSD locations were transposed to common imaging space to study anatomical location, functional network localization and relationship to normal MTOR gene expression. All patients presented with stereotyped focal seizures with rapidly escalating frequency, prompting hospitalization in 48%. Despite 42% patients having seizure remissions, usually with sodium channel blocking medications, most eventually became drug-resistant and underwent surgery (86% seizure-free). Prior developmental delay was uncommon but intellectual, language and executive dysfunction were present in 24%, 48% and 29% when assessed preoperatively, low intellect being associated with greater epilepsy duration. BOSDs were missed on initial MRI in 68%, being ultimately recognized following repeat MRI, 18F-FDG-PET or image postprocessing. MRI features were grey-white junction blurring (100%), cortical thickening (91%), transmantle band (62%), increased cortical T1 signal (46%) and increased subcortical FLAIR signal (26%). BOSD hypometabolism was present on 18F-FDG-PET in 99%. Additional areas of cortical malformation or grey matter heterotopia were present in eight patients. BOSDs predominated in frontal and pericentral cortex and related functional networks, mostly sparing temporal and occipital cortex, and limbic and visual networks. Genetic testing yielded pathogenic mTOR pathway variants in 63% patients, including somatic MTOR variants in 47% operated patients and germline DEPDC5 or NPRL3 variants in 73% patients with familial focal epilepsy. BOSDs tended to occur in regions where the healthy brain normally shows lower MTOR expression, suggesting these regions may be more vulnerable to upregulation of MTOR activity. Consistent with the existing literature, these results highlight (i) clinical features raising suspicion of BOSD; (ii) the role of somatic and germline mTOR pathway variants in patients with sporadic and familial focal epilepsy associated with BOSD; and (iii) the role of 18F-FDG-PET alongside high-field MRI in detecting subtle BOSD. The anatomical and functional distribution of BOSDs likely explain their seizure, EEG and cognitive manifestations and may relate to relative MTOR expression.
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Affiliation(s)
- Emma Macdonald-Laurs
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Aaron E L Warren
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Medicine (Austin Health), The University of Melbourne, Heidelberg 3084, Australia
| | - Peter Francis
- Department of Medical Imaging, The Royal Children's Hospital, Parkville 3052, Australia
| | - Simone A Mandelstam
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Medical Imaging, The Royal Children's Hospital, Parkville 3052, Australia
| | - Wei Shern Lee
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Matthew Coleman
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Sarah E M Stephenson
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Sarah Barton
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Colleen D'Arcy
- Department of Pathology, The Royal Children's Hospital, Parkville 3052, Australia
| | - Paul J Lockhart
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Department of Genomic Medicine, Bruce Lefroy Centre, Murdoch Children's Research Institute, Parkville 3052, Australia
| | - Richard J Leventer
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - A Simon Harvey
- Department of Neurology, The Royal Children's Hospital, Parkville, Victoria 3052Australia
- Department of Neuroscience, Murdoch Children's Research Institute, Parkville 3052, Australia
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
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3
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McGinley C, Teti S, Hofmann K, Schreiber JM, Cohen NT, Gaillard WD, Oluigbo CO. Seizure Control Outcomes following Resection of Cortical Dysplasia in Patients with DEPDC5 Variants: A Systematic Review and Individual Patient Data Analysis. Neuropediatrics 2024; 55:1-8. [PMID: 37984419 DOI: 10.1055/a-2213-8584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
There is insufficient evidence regarding the efficacy of epilepsy surgery in patients with pharmacoresistant focal epilepsy and coexistent DEPDC5 (dishevelled EGL-10 and pleckstrin domain-containing protein 5) pathogenic (P), likely pathogenic (LP), or variance of unknown significance (VUS) variants. To conduct a systematic review on the literature regarding the use and efficacy of epilepsy surgery as an intervention for patients with DEPDC5 variants who have pharmacoresistant epilepsy. A systematic review of the current literature published regarding the outcomes of epilepsy surgery for patients with DEPDC5 variants was conducted. Demographics and individual patient data were recorded and analyzed. Subsequent statistical analysis was performed to assess significance of the findings. A total of eight articles comprising 44 DEPDC5 patients with genetic variants undergoing surgery were included in this study. The articles primarily originated in high-income countries (5/8, 62.5%). The average age of the subjects was 10.06 ± 9.41 years old at the time of study. The most common form of epilepsy surgery was focal resection (38/44, 86.4%). Thirty-seven of the 40 patients (37/40, 92.5%) with reported seizure frequency results had improvement. Twenty-nine out of 38 patients (29/38, 78.4%) undergoing focal resection achieved Engel Score I postoperatively, and two out of four patients achieved International League Against Epilepsy I (50%). Epilepsy surgery is effective in patients with pharmacoresistant focal epilepsy and coexistent DEPDC5 P, LP, or VUS variants.
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Affiliation(s)
- Christopher McGinley
- College of Medicine, Howard University College of Medicine, Washington, District of Columbia, United States
| | - Saige Teti
- Division of Neurosurgery, Children's National Hospital, Washington, District of Columbia, United States
| | - Katherine Hofmann
- Division of Neurosurgery, Children's National Hospital, Washington, District of Columbia, United States
| | - John M Schreiber
- Division of Neurology, Children's National Hospital, Washington, District of Columbia, United States
| | - Nathan T Cohen
- Division of Neurology, Children's National Hospital, Washington, District of Columbia, United States
| | - William D Gaillard
- Division of Neurosurgery, Children's National Hospital, Washington, District of Columbia, United States
| | - Chima O Oluigbo
- Division of Neurosurgery, Children's National Hospital, Washington, District of Columbia, United States
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4
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Eriksson MH, Whitaker KJ, Booth J, Piper RJ, Chari A, Sanfilippo PM, Caballero AP, Menzies L, McTague A, Adler S, Wagstyl K, Tisdall MM, Cross JH, Baldeweg T. Pediatric epilepsy surgery from 2000 to 2018: Changes in referral and surgical volumes, patient characteristics, genetic testing, and postsurgical outcomes. Epilepsia 2023; 64:2260-2273. [PMID: 37264783 PMCID: PMC7615891 DOI: 10.1111/epi.17670] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/25/2023] [Accepted: 05/31/2023] [Indexed: 06/03/2023]
Abstract
OBJECTIVE Neurosurgery is a safe and effective form of treatment for select children with drug-resistant epilepsy. Still, there is concern that it remains underutilized, and that seizure freedom rates have not improved over time. We investigated referral and surgical practices, patient characteristics, and postoperative outcomes over the past two decades. METHODS We performed a retrospective cohort study of children referred for epilepsy surgery at a tertiary center between 2000 and 2018. We extracted information from medical records and analyzed temporal trends using regression analyses. RESULTS A total of 1443 children were evaluated for surgery. Of these, 859 (402 females) underwent surgical resection or disconnection at a median age of 8.5 years (interquartile range [IQR] = 4.6-13.4). Excluding palliative procedures, 67% of patients were seizure-free and 15% were on no antiseizure medication (ASM) at 1-year follow-up. There was an annual increase in the number of referrals (7%, 95% confidence interval [CI] = 5.3-8.6; p < .001) and surgeries (4% [95% CI = 2.9-5.6], p < .001) over time. Duration of epilepsy and total number of different ASMs trialed from epilepsy onset to surgery were, however, unchanged, and continued to exceed guidelines. Seizure freedom rates were also unchanged overall but showed improvement (odds ratio [OR] 1.09, 95% CI = 1.01-1.18; p = .027) after adjustment for an observed increase in complex cases. Children who underwent surgery more recently were more likely to be off ASMs postoperatively (OR 1.04, 95% CI = 1.01-1.08; p = .013). There was a 17% annual increase (95% CI = 8.4-28.4, p < .001) in children identified to have a genetic cause of epilepsy, which was associated with poor outcome. SIGNIFICANCE Children with drug-resistant epilepsy continue to be put forward for surgery late, despite national and international guidelines urging prompt referral. Seizure freedom rates have improved over the past decades, but only after adjustment for a concurrent increase in complex cases. Finally, genetic testing in epilepsy surgery patients has expanded considerably over time and shows promise in identifying patients in whom surgery is less likely to be successful.
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Affiliation(s)
- Maria H Eriksson
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neuropsychology, Great Ormond Street Hospital NHS Trust, London, UK
- The Alan Turing Institute, London, UK
- Department of Neurology, Great Ormond Street Hospital NHS Trust, London, UK
| | | | - John Booth
- Digital Research Environment, Great Ormond Street Hospital NHS Trust, London, UK
| | - Rory J Piper
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurosurgery, Great Ormond Street Hospital NHS Trust, London, UK
| | - Aswin Chari
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurosurgery, Great Ormond Street Hospital NHS Trust, London, UK
| | - Patricia Martin Sanfilippo
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neuropsychology, Great Ormond Street Hospital NHS Trust, London, UK
| | - Ana Perez Caballero
- North Thames Genomic Laboratory Hub, Great Ormond Street Hospital NHS Trust, London, UK
| | - Lara Menzies
- Department of Clinical Genetics, Great Ormond Street Hospital NHS Trust, London, UK
| | - Amy McTague
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital NHS Trust, London, UK
| | - Sophie Adler
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Konrad Wagstyl
- Imaging Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Martin M Tisdall
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurosurgery, Great Ormond Street Hospital NHS Trust, London, UK
| | - J Helen Cross
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital NHS Trust, London, UK
- Young Epilepsy, Lingfield, UK
| | - Torsten Baldeweg
- Developmental Neurosciences Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neuropsychology, Great Ormond Street Hospital NHS Trust, London, UK
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5
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Lee HM, Hong SJ, Gill R, Caldairou B, Wang I, Zhang JG, Deleo F, Schrader D, Bartolomei F, Guye M, Cho KH, Barba C, Sisodiya S, Jackson G, Hogan RE, Wong-Kisiel L, Cascino GD, Schulze-Bonhage A, Lopes-Cendes I, Cendes F, Guerrini R, Bernhardt B, Bernasconi N, Bernasconi A. Multimodal mapping of regional brain vulnerability to focal cortical dysplasia. Brain 2023; 146:3404-3415. [PMID: 36852571 PMCID: PMC10393418 DOI: 10.1093/brain/awad060] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/17/2023] [Accepted: 02/02/2023] [Indexed: 03/01/2023] Open
Abstract
Focal cortical dysplasia (FCD) type II is a highly epileptogenic developmental malformation and a common cause of surgically treated drug-resistant epilepsy. While clinical observations suggest frequent occurrence in the frontal lobe, mechanisms for such propensity remain unexplored. Here, we hypothesized that cortex-wide spatial associations of FCD distribution with cortical cytoarchitecture, gene expression and organizational axes may offer complementary insights into processes that predispose given cortical regions to harbour FCD. We mapped the cortex-wide MRI distribution of FCDs in 337 patients collected from 13 sites worldwide. We then determined its associations with (i) cytoarchitectural features using histological atlases by Von Economo and Koskinas and BigBrain; (ii) whole-brain gene expression and spatiotemporal dynamics from prenatal to adulthood stages using the Allen Human Brain Atlas and PsychENCODE BrainSpan; and (iii) macroscale developmental axes of cortical organization. FCD lesions were preferentially located in the prefrontal and fronto-limbic cortices typified by low neuron density, large soma and thick grey matter. Transcriptomic associations with FCD distribution uncovered a prenatal component related to neuroglial proliferation and differentiation, likely accounting for the dysplastic makeup, and a postnatal component related to synaptogenesis and circuit organization, possibly contributing to circuit-level hyperexcitability. FCD distribution showed a strong association with the anterior region of the antero-posterior axis derived from heritability analysis of interregional structural covariance of cortical thickness, but not with structural and functional hierarchical axes. Reliability of all results was confirmed through resampling techniques. Multimodal associations with cytoarchitecture, gene expression and axes of cortical organization indicate that prenatal neurogenesis and postnatal synaptogenesis may be key points of developmental vulnerability of the frontal lobe to FCD. Concordant with a causal role of atypical neuroglial proliferation and growth, our results indicate that FCD-vulnerable cortices display properties indicative of earlier termination of neurogenesis and initiation of cell growth. They also suggest a potential contribution of aberrant postnatal synaptogenesis and circuit development to FCD epileptogenicity.
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Affiliation(s)
- Hyo M Lee
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Seok-Jun Hong
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
- Center for Neuroscience Imaging, Research Institute for Basic Science, Department of Global Biomedical Engineering, SungKyunKwan University, Suwon, KoreaSuwon, Korea
| | - Ravnoor Gill
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Benoit Caldairou
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Irene Wang
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jian-guo Zhang
- Department of Functional Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Francesco Deleo
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico C. Besta, Milano, Italy
| | - Dewi Schrader
- Department of Pediatrics, British Columbia Children’s Hospital, Vancouver, Canada
| | - Fabrice Bartolomei
- Aix Marseille Univ, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, 13005, France
| | - Maxime Guye
- Aix Marseille University, CNRS, CRMBM UMR 7339, Marseille, France
| | - Kyoo Ho Cho
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
| | - Carmen Barba
- Meyer Children's Hospital IRCCS, Florence, Italy
- University of Florence, 50121 Florence, Italy
| | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Graeme Jackson
- The Florey Institute of Neuroscience and Mental Health and The University of Melbourne, Victoria, Australia
| | - R Edward Hogan
- Department of Neurology, Washington University School of Medicine, St Louis, MO, USA
| | | | | | | | - Iscia Lopes-Cendes
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP) and the Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas SP, Brazil
| | - Fernando Cendes
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), and the Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas SP, Brazil
| | - Renzo Guerrini
- Meyer Children's Hospital IRCCS, Florence, Italy
- University of Florence, 50121 Florence, Italy
| | - Boris Bernhardt
- Multimodal Imaging and Connectome Analysis Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Laboratory, Montreal Neurological Institute, McGill University, Montreal, Canada
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Sahly AN, Whitney R, Costain G, Chau V, Otsubo H, Ochi A, Donner EJ, Cunningham J, Jones KC, Widjaja E, Ibrahim GM, Jain P. Epilepsy surgery outcomes in patients with GATOR1 gene complex variants: Report of new cases and review of literature. Seizure 2023; 107:13-20. [PMID: 36931189 DOI: 10.1016/j.seizure.2023.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/19/2023] [Accepted: 03/09/2023] [Indexed: 03/13/2023] Open
Abstract
AIM To report seizure outcomes in children with GATOR1 gene complex disorders who underwent epilepsy surgery and perform a systematic literature search to study the available evidence. METHODS The records of children with pathogenic/likely pathogenic variants in GATOR1 gene complex who underwent epilepsy surgery were reviewed. Clinical, radiological, neurophysiological, and histological data were extracted/summarized. The systematic review included all case series/reports and observational studies reporting on children or adults with genetic (germline or somatic) variants in the GATOR1 complex genes (DEPDC5, NPRL2, NPRL3) with focal epilepsy with/without focal cortical dysplasia who underwent epilepsy surgery; seizure outcomes were analyzed. RESULTS Eight children with pathogenic/likely pathogenic variants in GATOR1 complex genes were included. All had drug-resistant epilepsy. Six children had significant neurodevelopmental delay. Epilepsy surgery was performed in all; clinical seizure freedom was noted in 4 children (50%). Systematic literature search identified 17 eligible articles; additional 30 cases with patient-level data were studied. Lesional MRI brain was seen in 80% cases. The pooled rate of seizure freedom following surgery was 60%; FCD IIa was the most encountered pathology. INTERPRETATION Epilepsy surgery may be effective in some children with GATOR1 complex gene variants. Seizure outcomes may be compromised by extensive epileptogenic zones.
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Affiliation(s)
- Ahmed N Sahly
- Division of Neurology, Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada; Department of Neurosciences, King Faisal Specialist Hospital & Research Centre, Jeddah, Saudi Arabia
| | - Robyn Whitney
- Division of Neurology, Department of Paediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Vann Chau
- Division of Neurology, Department of Paediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Hiroshi Otsubo
- Division of Neurology, Department of Paediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ayako Ochi
- Division of Neurology, Department of Paediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Elizabeth J Donner
- Division of Neurology, Department of Paediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jessie Cunningham
- Hospital Library and Archives, Learning Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Kevin C Jones
- Division of Neurology, Department of Paediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Elysa Widjaja
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Ontario, Canada
| | - George M Ibrahim
- Division of Neurosurgery, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Puneet Jain
- Division of Neurology, Department of Paediatrics, Hospital for Sick Children, Toronto, Ontario, Canada.
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Jansen RM, Hurley JH. Longin domain GAP complexes in nutrient signalling, membrane traffic and neurodegeneration. FEBS Lett 2023; 597:750-761. [PMID: 36367440 PMCID: PMC10050129 DOI: 10.1002/1873-3468.14538] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
Small GTPases act as molecular switches and control numerous cellular processes by their binding and hydrolysis of guanosine triphosphate (GTP). The activity of small GTPases is coordinated by guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). Recent structural and functional studies have characterized a subset of GAPs whose catalytic units consist of longin domains. Longin domain containing GAPs regulate small GTPases that facilitate nutrient signalling, autophagy, vesicular trafficking and lysosome homeostasis. All known examples in this GAP family function as part of larger multiprotein complexes. The three characterized mammalian protein complexes in this class are FLCN:FNIP, GATOR1 and C9orf72:SMCR8. Each complex carries out a unique cellular function by regulating distinct small GTPases. In this article, we explore the roles of longin domain GAPs in nutrient sensing, membrane dynamic, vesicular trafficking and disease. Through a structural lens, we examine the mechanism of each longin domain GAP and highlight potential therapeutic applications.
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Affiliation(s)
- Rachel M. Jansen
- Department of Molecular and Cell Biology, University of California Berkeley; Berkeley CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
| | - James H. Hurley
- Department of Molecular and Cell Biology, University of California Berkeley; Berkeley CA 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
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8
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Human In Vitro Models of Epilepsy Using Embryonic and Induced Pluripotent Stem Cells. Cells 2022; 11:cells11243957. [PMID: 36552721 PMCID: PMC9776452 DOI: 10.3390/cells11243957] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 12/04/2022] [Indexed: 12/14/2022] Open
Abstract
The challenges in making animal models of complex human epilepsy phenotypes with varied aetiology highlights the need to develop alternative disease models that can address the limitations of animal models by effectively recapitulating human pathophysiology. The advances in stem cell technology provide an opportunity to use human iPSCs to make disease-in-a-dish models. The focus of this review is to report the current information and progress in the generation of epileptic patient-specific iPSCs lines, isogenic control cell lines, and neuronal models. These in vitro models can be used to study the underlying pathological mechanisms of epilepsies, anti-seizure medication resistance, and can also be used for drug testing and drug screening with their isogenic control cell lines.
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9
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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
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10
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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.
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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.
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11
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Hui JB, Silva JCH, Pelaez MC, Sévigny M, Venkatasubramani JP, Plumereau Q, Chahine M, Proulx CD, Sephton CF, Dutchak PA. NPRL2 Inhibition of mTORC1 Controls Sodium Channel Expression and Brain Amino Acid Homeostasis. eNeuro 2022; 9:ENEURO.0317-21.2022. [PMID: 35165201 PMCID: PMC8896560 DOI: 10.1523/eneuro.0317-21.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 12/19/2022] Open
Abstract
Genetic mutations in nitrogen permease regulator-like 2 (NPRL2) are associated with a wide spectrum of familial focal epilepsies, autism, and sudden unexpected death of epileptics (SUDEP), but the mechanisms by which NPRL2 contributes to these effects are not well known. NPRL2 is a requisite subunit of the GAP activity toward Rags 1 (GATOR1) complex, which functions as a negative regulator of mammalian target of rapamycin complex 1 (mTORC1) kinase when intracellular amino acids are low. Here, we show that loss of NPRL2 expression in mouse excitatory glutamatergic neurons causes seizures before death, consistent with SUDEP in humans with epilepsy. Additionally, the absence of NPRL2 expression increases mTORC1-dependent signal transduction and significantly alters amino acid homeostasis in the brain. Loss of NPRL2 reduces dendritic branching and increases the strength of electrically stimulated action potentials (APs) in neurons. The increased AP strength is consistent with elevated expression of epilepsy-linked, voltage-gated sodium channels in the NPRL2-deficient brain. Targeted deletion of NPRL2 in primary neurons increases the expression of sodium channel Scn1A, whereas treatment with the pharmacological mTORC1 inhibitor called rapamycin prevents Scn1A upregulation. These studies demonstrate a novel role of NPRL2 and mTORC1 signaling in the regulation of sodium channels, which can contribute to seizures and early lethality.
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Affiliation(s)
- Jeremy B Hui
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Jose Cesar Hernandez Silva
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Mari Carmen Pelaez
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Myriam Sévigny
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Janani Priya Venkatasubramani
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Quentin Plumereau
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Mohamed Chahine
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Christophe D Proulx
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Chantelle F Sephton
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
| | - Paul A Dutchak
- Department of Psychiatry and Neuroscience, CERVO Brain Research Centre, Université Laval, Quebec City, Quebec G1J 2G3, Canada
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12
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Zhang J, Shen Y, Yang Z, Yang F, Li Y, Yu B, Chen W, Gan J. A splicing variation in NPRL2 causing familial focal epilepsy with variable foci: additional cases and literature review. J Hum Genet 2022; 67:79-85. [PMID: 34376795 PMCID: PMC8786660 DOI: 10.1038/s10038-021-00969-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 01/31/2023]
Abstract
NPRL2 (nitrogen permease regulator like 2) is a component of the GATOR1(GAP activity towards rags complex 1) proteins, which is an inhibitor of the amino acid-sensing branch of the mTORC1 pathway. GATOR1 complex variations were reported to correlate with familial focal epilepsy with variable foci (FFEVF). However, FFEVF caused by NPRL2 variants has not been widely explored. Here, we describe a variant, 339+2T>C, in NPRL2 identified by trio whole-exome sequencing (WES) in a family. This splicing variant that occurred at the 5' end of exon 3 was confirmed by minigene assays, which affected alternative splicing and led to exon 3 skipping in NPRL2. Our cases presented multiple seizure types (febrile seizures, infantile spasms, focal seizures, or focal to generalized tonic-clonic seizures). Electroencephalogram (EEG) showed frequent discharges in the left frontal and central regions. A favorable prognosis was achieved in response to vitamin B6 and topiramate when the patient was seven months old. Our study expands the phenotype and genotype spectrum of FFEVF and provides solid diagnostic evidence for FFEVF.
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Affiliation(s)
- Jia Zhang
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Yajun Shen
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | | | | | - Yang Li
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, Sichuan, China
| | - Bo Yu
- Department of Pediatrics, The City Central Hospital of Wanyuan, Wanyuan, Sichuan, China
| | - Wanlin Chen
- Department of Pediatrics, The City Central Hospital of Wanyuan, Wanyuan, Sichuan, China
| | - Jing Gan
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.
- Key Laboratory of Obstetrics & Gynecologic and Pediatric Diseases and Birth Defects of the Ministry of Education, Sichuan University, Chengdu, Sichuan, China.
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13
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Bennett MF, Hildebrand MS, Kayumi S, Corbett MA, Gupta S, Ye Z, Krivanek M, Burgess R, Henry OJ, Damiano JA, Boys A, Gécz J, Bahlo M, Scheffer IE, Berkovic SF. Evidence for a Dual-Pathway, 2-Hit Genetic Model for Focal Cortical Dysplasia and Epilepsy. NEUROLOGY GENETICS 2022; 8:e652. [PMID: 35097204 PMCID: PMC8789218 DOI: 10.1212/nxg.0000000000000652] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/03/2021] [Indexed: 12/31/2022]
Abstract
Background and Objectives The 2-hit model of genetic disease is well established in cancer, yet has
only recently been reported to cause brain malformations associated with
epilepsy. Pathogenic germline and somatic variants in genes in the
mechanistic target of rapamycin (mTOR) pathway have been implicated in
several malformations of cortical development. We investigated the 2-hit
model by performing genetic analysis and searching for germline and somatic
variants in genes in the mTOR and related pathways. Methods We searched for germline and somatic pathogenic variants in 2 brothers with
drug-resistant focal epilepsy and surgically resected focal cortical
dysplasia (FCD) type IIA. Exome sequencing was performed on blood- and
brain-derived DNA to identify pathogenic variants, which were validated by
droplet digital PCR. In vitro functional assays of a somatic variant were
performed. Results Exome analysis revealed a novel, maternally inherited, germline pathogenic
truncation variant (c.48delG; p.Ser17Alafs*70) in
NPRL3 in both brothers. NPRL3 is a
known FCD gene that encodes a negative regulator of the mTOR pathway.
Somatic variant calling in brain-derived DNA from both brothers revealed a
low allele fraction somatic variant (c.338C>T; p.Ala113Val) in the
WNT2 gene in 1 brother, confirmed by droplet digital
PCR. In vitro functional studies suggested a loss of WNT2 function as a
consequence of this variant. A second somatic variant has not yet been found
in the other brother. Discussion We identify a pathogenic germline mTOR pathway variant
(NPRL3) and a somatic variant (WNT2)
in the intersecting WNT signaling pathway, potentially implicating the
WNT2 gene in FCD and supporting a dual-pathway 2-hit
model. If confirmed in other cases, this would extend the 2-hit model to
pathogenic variants in different genes in critical, intersecting pathways in
a malformation of cortical development. Detection of low allele fraction
somatic second hits is challenging but promises to unravel the molecular
architecture of FCDs.
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14
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Lee WS, Baldassari S, Stephenson SEM, Lockhart PJ, Baulac S, Leventer RJ. Cortical Dysplasia and the mTOR Pathway: How the Study of Human Brain Tissue Has Led to Insights into Epileptogenesis. Int J Mol Sci 2022; 23:1344. [PMID: 35163267 PMCID: PMC8835853 DOI: 10.3390/ijms23031344] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/14/2022] [Accepted: 01/16/2022] [Indexed: 02/01/2023] Open
Abstract
Type II focal cortical dysplasia (FCD) is a neuropathological entity characterised by cortical dyslamination with the presence of dysmorphic neurons only (FCDIIA) or the presence of both dysmorphic neurons and balloon cells (FCDIIB). The year 2021 marks the 50th anniversary of the recognition of FCD as a cause of drug resistant epilepsy, and it is now the most common reason for epilepsy surgery. The causes of FCD remained unknown until relatively recently. The study of resected human FCD tissue using novel genomic technologies has led to remarkable advances in understanding the genetic basis of FCD. Mechanistic parallels have emerged between these non-neoplastic lesions and neoplastic disorders of cell growth and differentiation, especially through perturbations of the mammalian target of rapamycin (mTOR) signalling pathway. This narrative review presents the advances through which the aetiology of FCDII has been elucidated in chronological order, from recognition of an association between FCD and the mTOR pathway to the identification of somatic mosaicism within FCD tissue. We discuss the role of a two-hit mechanism, highlight current challenges and future directions in detecting somatic mosaicism in brain and discuss how knowledge of FCD may inform novel precision treatments of these focal epileptogenic malformations of human cortical development.
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Affiliation(s)
- Wei Shern Lee
- Bruce Lefroy Centre, Murdoch Children’s Research Institute, Parkville 3052, Australia; (W.S.L.); (S.E.M.S.); (P.J.L.)
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Sara Baldassari
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013 Paris, France;
| | - Sarah E. M. Stephenson
- Bruce Lefroy Centre, Murdoch Children’s Research Institute, Parkville 3052, Australia; (W.S.L.); (S.E.M.S.); (P.J.L.)
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Paul J. Lockhart
- Bruce Lefroy Centre, Murdoch Children’s Research Institute, Parkville 3052, Australia; (W.S.L.); (S.E.M.S.); (P.J.L.)
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
| | - Stéphanie Baulac
- Institut du Cerveau-Paris Brain Institute-ICM, Sorbonne Université, Inserm, CNRS, Hôpital de la Pitié Salpêtrière, F-75013 Paris, France;
| | - Richard J. Leventer
- Department of Paediatrics, The University of Melbourne, Parkville 3052, Australia
- Murdoch Children’s Research Institute, Parkville 3052, Australia
- Department of Neurology, The Royal Children’s Hospital, Parkville 3052, Australia
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15
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Ishida S, Zhao D, Sawada Y, Hiraoka Y, Mashimo T, Tanaka K. Dorsal telencephalon-specific Nprl2- and Nprl3-knockout mice: novel mouse models for GATORopathy. Hum Mol Genet 2021; 31:1519-1530. [PMID: 34965576 PMCID: PMC9071434 DOI: 10.1093/hmg/ddab337] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 09/28/2021] [Accepted: 11/12/2021] [Indexed: 11/30/2022] Open
Abstract
The most frequent genetic cause of focal epilepsies is variations in the GAP activity toward RAGs 1 complex genes DEP domain containing 5 (DEPDC5), nitrogen permease regulator 2-like protein (NPRL2) and nitrogen permease regulator 3-like protein (NPRL3). Because these variations are frequent and associated with a broad spectrum of focal epilepsies, a unique pathology categorized as GATORopathy can be conceptualized. Animal models recapitulating the clinical features of patients are essential to decipher GATORopathy. Although several genetically modified animal models recapitulate DEPDC5-related epilepsy, no models have been reported for NPRL2- or NPRL3-related epilepsies. Here, we conditionally deleted Nprl2 and Nprl3 from the dorsal telencephalon in mice [Emx1cre/+; Nprl2f/f (Nprl2-cKO) and Emx1cre/+; Nprl3f/f (Nprl3-cKO)] and compared their phenotypes with Nprl2+/−, Nprl3+/− and Emx1cre/+; Depdc5f/f (Depdc5-cKO) mice. Nprl2-cKO and Nprl3-cKO mice recapitulated the major abnormal features of patients—spontaneous seizures, and dysmorphic enlarged neuronal cells with increased mechanistic target of rapamycin complex 1 signaling—similar to Depdc5-cKO mice. Chronic postnatal rapamycin administration dramatically prolonged the survival period and inhibited seizure occurrence but not enlarged neuronal cells in Nprl2-cKO and Nprl3-cKO mice. However, the benefit of rapamycin after withdrawal was less durable in Nprl2- and Nprl3-cKO mice compared with Depdc5-cKO mice. Further studies using these conditional knockout mice will be useful for understanding GATORopathy and for the identification of novel therapeutic targets.
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Affiliation(s)
- Saeko Ishida
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Division of Animal Genetics, Laboratory Animal Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Di Zhao
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Division of Animal Genetics, Laboratory Animal Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Yuta Sawada
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
| | - Yuichi Hiraoka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Laboratory of Genome Editing for Biomedical Research, MRI, TMDU, Tokyo, 101-0062, Japan
| | - Tomoji Mashimo
- Division of Animal Genetics, Laboratory Animal Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 113-8510, Japan
- Center for Brain Integration Research (CBIR), TMDU, Tokyo, 113-8510, Japan
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16
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Pharmacogenetics of Drug-Resistant Epilepsy (Review of Literature). Int J Mol Sci 2021; 22:ijms222111696. [PMID: 34769124 PMCID: PMC8584095 DOI: 10.3390/ijms222111696] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/25/2021] [Accepted: 10/27/2021] [Indexed: 12/17/2022] Open
Abstract
Pharmacogenomic studies in epilepsy are justified by the high prevalence rate of this disease and the high cost of its treatment, frequent drug resistance, different response to the drug, the possibility of using reliable methods to assess the control of seizures and side effects of antiepileptic drugs. Candidate genes encode proteins involved in pharmacokinetic processes (drug transporters, metabolizing enzymes), pharmacodynamic processes (receptors, ion channels, enzymes, regulatory proteins, secondary messengers) and drug hypersensitivity (immune factors). This article provides an overview of the literature on the influence of genetic factors on treatment in epilepsy.
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17
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Moloney PB, Cavalleri GL, Delanty N. Epilepsy in the mTORopathies: opportunities for precision medicine. Brain Commun 2021; 3:fcab222. [PMID: 34632383 PMCID: PMC8495134 DOI: 10.1093/braincomms/fcab222] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 01/16/2023] Open
Abstract
The mechanistic target of rapamycin signalling pathway serves as a ubiquitous regulator of cell metabolism, growth, proliferation and survival. The main cellular activity of the mechanistic target of rapamycin cascade funnels through mechanistic target of rapamycin complex 1, which is inhibited by rapamycin, a macrolide compound produced by the bacterium Streptomyces hygroscopicus. Pathogenic variants in genes encoding upstream regulators of mechanistic target of rapamycin complex 1 cause epilepsies and neurodevelopmental disorders. Tuberous sclerosis complex is a multisystem disorder caused by mutations in mechanistic target of rapamycin regulators TSC1 or TSC2, with prominent neurological manifestations including epilepsy, focal cortical dysplasia and neuropsychiatric disorders. Focal cortical dysplasia type II results from somatic brain mutations in mechanistic target of rapamycin pathway activators MTOR, AKT3, PIK3CA and RHEB and is a major cause of drug-resistant epilepsy. DEPDC5, NPRL2 and NPRL3 code for subunits of the GTPase-activating protein (GAP) activity towards Rags 1 complex (GATOR1), the principal amino acid-sensing regulator of mechanistic target of rapamycin complex 1. Germline pathogenic variants in GATOR1 genes cause non-lesional focal epilepsies and epilepsies associated with malformations of cortical development. Collectively, the mTORopathies are characterized by excessive mechanistic target of rapamycin pathway activation and drug-resistant epilepsy. In the first large-scale precision medicine trial in a genetically mediated epilepsy, everolimus (a synthetic analogue of rapamycin) was effective at reducing seizure frequency in people with tuberous sclerosis complex. Rapamycin reduced seizures in rodent models of DEPDC5-related epilepsy and focal cortical dysplasia type II. This review outlines a personalized medicine approach to the management of epilepsies in the mTORopathies. We advocate for early diagnostic sequencing of mechanistic target of rapamycin pathway genes in drug-resistant epilepsy, as identification of a pathogenic variant may point to an occult dysplasia in apparently non-lesional epilepsy or may uncover important prognostic information including, an increased risk of sudden unexpected death in epilepsy in the GATORopathies or favourable epilepsy surgery outcomes in focal cortical dysplasia type II due to somatic brain mutations. Lastly, we discuss the potential therapeutic application of mechanistic target of rapamycin inhibitors for drug-resistant seizures in GATOR1-related epilepsies and focal cortical dysplasia type II.
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Affiliation(s)
- Patrick B Moloney
- FutureNeuro, the Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, Dublin, D02 VN51, Ireland
| | - Gianpiero L Cavalleri
- FutureNeuro, the Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, Dublin, D02 VN51, Ireland
| | - Norman Delanty
- FutureNeuro, the Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, Dublin, D02 VN51, Ireland
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18
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Marashly A, Karia S, Zonjy B. Epilepsy Surgery: Special Circumstances. Semin Pediatr Neurol 2021; 39:100921. [PMID: 34620459 DOI: 10.1016/j.spen.2021.100921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 08/16/2021] [Accepted: 08/24/2021] [Indexed: 11/25/2022]
Abstract
Epilepsy surgery has proven to be very effective in treating refractory focal epilepsies in children, producing seizure freedom or partial seizure control well beyond any other medical or dietary therapies. While surgery is mostly utilized in certain clinical phenotypes, either based on the location such as temporal lobe epilepsy, or based on the presence of known epileptogenic lesions such as focal cortical dysplasia, tumors or hemimegalencephaly, there is a growing body of evidence to support the role of surgery in other patients' cohorts that were classically not thought of as surgical candidates. These include patients with rare genetic disorders, electrical status epilepticus in sleep, status epilepticus and the very young patients. Furthermore, epilepsy surgery is not considered as a "last resort" as seizure and cognitive outcomes of surgery are considerably better when done earlier rather than later in relation to the time of onset of epilepsy and age of surgery especially in the context of known focal cortical dysplasia. This article examines the accumulating evidence of the utility of epilepsy surgery in these special circumstances.
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Affiliation(s)
- Ahmad Marashly
- Assistant Professor, University of Washington/Seattle Children's Hospital, Seattle, WA.
| | - Samir Karia
- Associate Professor, Univeristy of Louisville, Luisiville, KY
| | - Bilal Zonjy
- Assistant Professor, University of Washington/Seattle Children's Hospital, Seattle, WA
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19
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Klofas LK, Short BP, Zhou C, Carson RP. Prevention of premature death and seizures in a Depdc5 mouse epilepsy model through inhibition of mTORC1. Hum Mol Genet 2021; 29:1365-1377. [PMID: 32280987 DOI: 10.1093/hmg/ddaa068] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
Mutations in DEP domain containing 5 (DEPDC5) are increasingly appreciated as one of the most common causes of inherited focal epilepsy. Epilepsies due to DEPDC5 mutations are often associated with brain malformations, tend to be drug-resistant, and have been linked to an increased risk of sudden unexplained death in epilepsy (SUDEP). Generation of epilepsy models to define mechanisms of epileptogenesis remains vital for future therapies. Here, we describe a novel mouse model of Depdc5 deficiency with a severe epilepsy phenotype, generated by conditional deletion of Depdc5 in dorsal telencephalic neuroprogenitor cells. In contrast to control and heterozygous mice, Depdc5-Emx1-Cre conditional knockout (CKO) mice demonstrated macrocephaly, spontaneous seizures and premature death. Consistent with increased mTORC1 activation, targeted neurons were enlarged and both neurons and astrocytes demonstrated increased S6 phosphorylation. Electrophysiologic characterization of miniature inhibitory post-synaptic currents in excitatory neurons was consistent with impaired post-synaptic response to GABAergic input, suggesting a potential mechanism for neuronal hyperexcitability. mTORC1 inhibition with rapamycin significantly improved survival of CKO animals and prevented observed seizures, including for up to 40 days following rapamycin withdrawal. These data not only support a primary role for mTORC1 hyperactivation in epilepsy following homozygous loss of Depdc5, but also suggest a developmental window for treatment which may have a durable benefit for some time even after withdrawal.
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Affiliation(s)
- Lindsay K Klofas
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Brittany P Short
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Robert P Carson
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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20
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Zhang X, Huang Z, Liu J, Li M, Zhao X, Ye J, Wang Y. Phenotypic and Genotypic Characterization of DEPDC5-Related Familial Focal Epilepsy: Case Series and Literature Review. Front Neurol 2021; 12:641019. [PMID: 34239491 PMCID: PMC8258162 DOI: 10.3389/fneur.2021.641019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 04/21/2021] [Indexed: 01/05/2023] Open
Abstract
Mutations in the disheveled, Egl-10 and domain-containing protein 5 (DEPDC5) recently have been identified as a common cause of focal epilepsy syndromes. The association between phenotype and genotype of DEPDC5 mutation has not been adequately characterized. We studied four families with familial focal epilepsy carrying DEPDC5 mutations. Four novel DEPDC5 mutations were identified by next-generation sequencing, including two missense mutations (c.1729 >A and c.3260G>A), one splicing mutation (c.280-1G>A), and one frameshift mutation (c.515_516delinsT). We found that patients carrying different DEPDC5 mutation have different clinical manifestations. Incomplete penetrance is a prominent feature of DEPDC5-related epilepsy, with the rate of penetrance ranging from 25 to 100%. About 21.4% of patients with DEPDC5-related familial focal epilepsy are refractory to treatments. We further reviewed the correlation of genotype and phenotype in all previous literature regarding DEPDC5-related epilepsy. Our study suggested that the type of DEPDC5 mutation might provide important information for the prognosis evaluation.
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Affiliation(s)
- Xuan Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Institute of Sleep and Consciousness Disorders, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Zhaoyang Huang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Institute of Sleep and Consciousness Disorders, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Jianghong Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Institute of Sleep and Consciousness Disorders, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Mingyu Li
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Institute of Sleep and Consciousness Disorders, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Xiaoling Zhao
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Institute of Sleep and Consciousness Disorders, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Jing Ye
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Institute of Sleep and Consciousness Disorders, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Neuromodulation, Beijing, China.,Institute of Sleep and Consciousness Disorders, Beijing Institute of Brain Disorders, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
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21
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Rácz A, Becker AJ, Quesada CM, Borger V, Vatter H, Surges R, Elger CE. Post-Surgical Outcome and Its Determining Factors in Patients Operated on With Focal Cortical Dysplasia Type II-A Retrospective Monocenter Study. Front Neurol 2021; 12:666056. [PMID: 34177771 PMCID: PMC8220082 DOI: 10.3389/fneur.2021.666056] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/19/2021] [Indexed: 11/27/2022] Open
Abstract
Purpose: Focal cortical dysplasias (FCDs) are a frequent cause of drug-resistant focal epilepsies. These lesions are in many cases amenable to epilepsy surgery. We examined 12-month and long-term post-surgical outcomes and its predictors including positive family history of epilepsy. Methods: Twelve-month and long-term outcomes regarding seizure control after epilepsy surgery in patients operated on with FCD type II between 2002 and 2019 in the Epilepsy Center of Bonn were evaluated based on patient records and telephone interviews. Results: Overall, 102 patients fulfilled the inclusion criteria. Seventy-one percent of patients at 12 months of follow-up (FU) and 54% of patients at the last available FU (63 ± 5.00 months, median 46.5 months) achieved complete seizure freedom (Engel class IA), and 84 and 69% of patients, respectively, displayed Engel class I outcome. From the examined variables [histopathology: FCD IIA vs. IIB, lobar lesion location: frontal vs. non-frontal, family history for epilepsy, focal to bilateral tonic–clonic seizures (FTBTCS) in case history, completeness of resection, age at epilepsy onset, age at surgery, duration of epilepsy], outcomes at 12 months were determined by interactions of age at onset, duration of epilepsy, age at surgery, extent of resection, and lesion location. Long-term post-surgical outcome was primarily influenced by the extent of resection and history of FTBTCS. Positive family history for epilepsy had a marginal influence on long-term outcomes only. Conclusion: Resective epilepsy surgery in patients with FCD II yields very good outcomes both at 12-month and long-term follow-ups. Complete lesion resection and the absence of FTBTCS prior to surgery are associated with a better outcome.
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Affiliation(s)
- Attila Rácz
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Albert J Becker
- Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Carlos M Quesada
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Valeri Borger
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Hartmut Vatter
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
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22
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Blümcke I, Coras R, Busch RM, Morita-Sherman M, Lal D, Prayson R, Cendes F, Lopes-Cendes I, Rogerio F, Almeida VS, Rocha CS, Sim NS, Lee JH, Kim SH, Baulac S, Baldassari S, Adle-Biassette H, Walsh CA, Bizzotto S, Doan RN, Morillo KS, Aronica E, Mühlebner A, Becker A, Cienfuegos J, Garbelli R, Giannini C, Honavar M, Jacques TS, Thom M, Mahadevan A, Miyata H, Niehusmann P, Sarnat HB, Söylemezoglu F, Najm I. Toward a better definition of focal cortical dysplasia: An iterative histopathological and genetic agreement trial. Epilepsia 2021; 62:1416-1428. [PMID: 33949696 DOI: 10.1111/epi.16899] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 03/22/2021] [Accepted: 03/23/2021] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Focal cortical dysplasia (FCD) is a major cause of difficult-to-treat epilepsy in children and young adults, and the diagnosis is currently based on microscopic review of surgical brain tissue using the International League Against Epilepsy classification scheme of 2011. We developed an iterative histopathological agreement trial with genetic testing to identify areas of diagnostic challenges in this widely used classification scheme. METHODS Four web-based digital pathology trials were completed by 20 neuropathologists from 15 countries using a consecutive series of 196 surgical tissue blocks obtained from 22 epilepsy patients at a single center. Five independent genetic laboratories performed screening or validation sequencing of FCD-relevant genes in paired brain and blood samples from the same 22 epilepsy patients. RESULTS Histopathology agreement based solely on hematoxylin and eosin stainings was low in Round 1, and gradually increased by adding a panel of immunostainings in Round 2 and the Delphi consensus method in Round 3. Interobserver agreement was good in Round 4 (kappa = .65), when the results of genetic tests were disclosed, namely, MTOR, AKT3, and SLC35A2 brain somatic mutations in five cases and germline mutations in DEPDC5 and NPRL3 in two cases. SIGNIFICANCE The diagnoses of FCD 1 and 3 subtypes remained most challenging and were often difficult to differentiate from a normal homotypic or heterotypic cortical architecture. Immunohistochemistry was helpful, however, to confirm the diagnosis of FCD or no lesion. We observed a genotype-phenotype association for brain somatic mutations in SLC35A2 in two cases with mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy. Our results suggest that the current FCD classification should recognize a panel of immunohistochemical stainings for a better histopathological workup and definition of FCD subtypes. We also propose adding the level of genetic findings to obtain a comprehensive, reliable, and integrative genotype-phenotype diagnosis in the near future.
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Affiliation(s)
- Ingmar Blümcke
- Department of Neuropathology, University Hospital, Erlangen, Germany.,Epilepsy Center, Cleveland Clinic, Cleveland, OH, USA
| | - Roland Coras
- Department of Neuropathology, University Hospital, Erlangen, Germany
| | - Robyn M Busch
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, USA.,Department of Neurology, Cleveland Clinic, Cleveland, OH, USA.,Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH, USA
| | | | - Dennis Lal
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, USA.,Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Richard Prayson
- Department of Anatomic Pathology, Cleveland Clinic, Cleveland, OH, USA
| | - Fernando Cendes
- Department of Neurology, University of Campinas, Sao Paulo, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology, Sao Paulo, Brazil
| | - Iscia Lopes-Cendes
- Brazilian Institute of Neuroscience and Neurotechnology, Sao Paulo, Brazil.,Department of Medical Genetics and Genomic Medicine, University of Campinas, Sao Paulo, Brazil
| | - Fabio Rogerio
- Brazilian Institute of Neuroscience and Neurotechnology, Sao Paulo, Brazil.,Department of Pathology, University of Campinas, Sao Paulo, Brazil
| | - Vanessa S Almeida
- Brazilian Institute of Neuroscience and Neurotechnology, Sao Paulo, Brazil.,Department of Medical Genetics and Genomic Medicine, University of Campinas, Sao Paulo, Brazil
| | - Cristiane S Rocha
- Brazilian Institute of Neuroscience and Neurotechnology, Sao Paulo, Brazil.,Department of Medical Genetics and Genomic Medicine, University of Campinas, Sao Paulo, Brazil
| | - Nam Suk Sim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Jeong Ho Lee
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,SoVarGen, Inc., Daejeon, Korea
| | - Se Hoon Kim
- Department of Pathology, College of Medicine, Yonsei University, Seoul, South Korea
| | - Stephanie Baulac
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France
| | - Sara Baldassari
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, Paris, France
| | - Homa Adle-Biassette
- Pathological Anatomy Service, Public Hospital Network of Paris, Paris, France.,NeuroDiderot, Inserm U1141, University of Paris, Paris, France
| | - Christopher A Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Department of Pediatrics, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | - Sara Bizzotto
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Department of Pediatrics, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | - Ryan N Doan
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Department of Pediatrics, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | - Katherine S Morillo
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Department of Pediatrics, and Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Departments of Pediatrics and Neurology, Harvard Medical School, Boston, MA, USA
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam UMC, location Academic Medical Center, Amsterdam, the Netherlands.,Epilepsy Institutes of the Netherlands Foundation, Heemstede, the Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam UMC, location Academic Medical Center, Amsterdam, the Netherlands.,Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Albert Becker
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
| | - Jesus Cienfuegos
- Department of Anatomic Pathology, International Center for Epilepsy Surgery, Humanitas Medical Group Hospital, Mexico City, Mexico.,Department of Anatomic Pathology, Angels Mexico Hospital, Mexico City, Mexico
| | - Rita Garbelli
- Epilepsy Unit, Carlo Besta Neurological Institute, Scientific Institute for Research and Health Care Foundation, Milan, Italy
| | - Caterina Giannini
- Anatomic Pathology, Mayo Clinic, Rochester, Minnesota, USA.,Department of Biomedical and Neuromotor Science,, Alma Mater Studiorum, University of Bologna, Bologna, Italy
| | - Mrinalini Honavar
- Department of Anatomic Pathology, Pedro Hispano Hospital, Matosinhos, Portugal
| | - Thomas S Jacques
- Developmental Biology and Cancer Research and Teaching Programme, University College London Great Ormond Street Institute of Child Health, London, UK.,Department of Histopathology, Great Ormond Street Hospital for Children, National Health Service Foundation Trust, London, UK
| | - Maria Thom
- Department of Neuropathology, Institute of Neurology, University College London, London, UK
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Hajime Miyata
- Department of Neuropathology, Research Institute for Brain and Blood Vessels, Akita Cerebrospinal and Cardiovascular Center, Akita, Japan
| | - Pitt Niehusmann
- Department of Neuro-/Pathology, Translational Neurodegeneration Research and Neuropathology Lab, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Harvey B Sarnat
- Department of Paediatrics, University of Calgary Faculty of Medicine, Alberta Children's Hospital Research Institute, Calgary, AB, Canada.,Department of Pathology (Neuropathology),, University of Calgary Faculty of Medicine, Alberta Children's Hospital Research Institute, Calgary, AB, Canada.,Department of Clinical Neurosciences, University of Calgary Faculty of Medicine, Alberta Children's Hospital Research Institute, Calgary, AB, Canada
| | - Figen Söylemezoglu
- Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Imad Najm
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, USA.,Department of Neurology, Cleveland Clinic, Cleveland, OH, USA
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23
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Balestrini S, Lopez SM, Chinthapalli K, Sargsyan N, Demurtas R, Vos S, Altmann A, Suttie M, Hammond P, Sisodiya SM. Increased facial asymmetry in focal epilepsies associated with unilateral lesions. Brain Commun 2021; 3:fcab068. [PMID: 34222868 PMCID: PMC8244637 DOI: 10.1093/braincomms/fcab068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 02/20/2021] [Accepted: 03/11/2021] [Indexed: 12/22/2022] Open
Abstract
The epilepsies are now conceptualized as network disruptions: focal epilepsies are considered to have network alterations in the hemisphere of seizure onset, whilst generalized epilepsies are considered to have bi-hemispheric network changes. Increasingly, many epilepsies are also considered to be neurodevelopmental disorders, with early changes in the brain underpinning seizure biology. The development of the structure of the face is influenced by complex molecular interactions between surface ectoderm and underlying developing forebrain and neural crest cells. This influence is likely to continue postnatally, given the evidence of facial growth changes over time in humans until at least 18 years of age. In this case-control study, we hypothesized that people with lateralized focal epilepsies (i.e. unilateral network changes) have an increased degree of facial asymmetry, compared with people with generalized epilepsies or controls without epilepsy. We applied three-dimensional stereophotogrammetry and dense surface models to evaluate facial asymmetry in people with epilepsy, aiming to generate new tools to explore pathophysiological mechanisms in epilepsy. We analysed neuroimaging data to explore the correlation between face and brain asymmetry. We consecutively recruited 859 people with epilepsy attending the epilepsy clinics at a tertiary referral centre. We used dense surface modelling of the full face and signature analyses of three-dimensional facial photographs to analyse facial differences between 378 cases and 205 healthy controls. Neuroimaging around the time of the facial photograph was available for 234 cases. We computed the brain asymmetry index between contralateral regions. Cases with focal symptomatic epilepsy associated with unilateral lesions showed greater facial asymmetry compared to controls (P = 0.0001, two-sample t-test). This finding was confirmed by linear regression analysis after controlling for age and gender. We also found a significant correlation between duration of illness and the brain asymmetry index of total average cortical thickness (r = -0.19, P = 0.0075) but not for total average surface area (r = 0.06, P = 0.3968). There was no significant correlation between facial asymmetry and asymmetry of regional cortical thickness or surface area. We propose that the greater facial asymmetry in cases with focal epilepsy caused by unilateral abnormality might be explained by early unilateral network disruption, and that this is independent of underlying brain asymmetry. Three-dimensional stereophotogrammetry and dense surface modelling are a novel powerful phenotyping tool in epilepsy that may permit greater understanding of pathophysiology in epilepsy, and generate further insights into the development of cerebral networks underlying epilepsy, and the genetics of facial and neural development.
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Affiliation(s)
- Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London.,Chalfont Centre for Epilepsy, Gerrards Cross, UK
| | - Seymour M Lopez
- Department of Medical Physics, Centre for Medical Image Computing, UCL, London, UK
| | - Krishna Chinthapalli
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London.,Chalfont Centre for Epilepsy, Gerrards Cross, UK
| | - Narek Sargsyan
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London.,Chalfont Centre for Epilepsy, Gerrards Cross, UK
| | - Rita Demurtas
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London.,Chalfont Centre for Epilepsy, Gerrards Cross, UK
| | - Sjoerd Vos
- Department of Medical Physics, Centre for Medical Image Computing, UCL, London, UK.,Neuroradiological Academic Unit, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Andre Altmann
- Department of Medical Physics, Centre for Medical Image Computing, UCL, London, UK
| | - Michael Suttie
- Nuffield Department of Women's & Reproductive Health, University of Oxford, Oxford, UK.,Big Data Institute, Old Road Campus, University of Oxford, Oxford, UK
| | - Peter Hammond
- Nuffield Department of Women's & Reproductive Health, University of Oxford, Oxford, UK.,Big Data Institute, Old Road Campus, University of Oxford, Oxford, UK
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London.,Chalfont Centre for Epilepsy, Gerrards Cross, UK
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24
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Salomone G, Comella M, Portale A, Pecora G, Costanza G, Lo Bianco M, Sciuto S, Praticò ER, Falsaperla R. The Spectrum of DEPDC5-Related Epilepsy. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractDisheveled EGL-10 and pleckstrin domain-containing protein 5 (DEPDC5) is a key member of the GAP activity toward rags complex 1 complex, which inhibits the mammalian target of rapamycin complex 1 (mTORC1) pathway. DEPDC5 loss-of-function mutations lead to an aberrant activation of the mTOR signaling. At neuronal level, the increased mTOR cascade causes the generation of epileptogenic dysplastic neuronal circuits and it is often associated with malformation of cortical development. The DEPDC5 phenotypic spectrum ranges from sporadic early-onset epilepsies with poor neurodevelopmental outcomes to familial focal epilepsies and sudden unexpected death in epilepsy; a high rate of inter- and intrafamilial variability has been reported. To date, clear genotype–phenotype correlations have not been proven. More studies are required to elucidate the significance of likely pathogenic/variants of uncertain significance. The pursuit of a molecular targeted antiepileptic therapy is a future challenge.
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Affiliation(s)
- Giulia Salomone
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Mattia Comella
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Anna Portale
- Unit of Pediatrics, Avola Hospital, Siracusa, Italy
| | - Giulia Pecora
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Giuseppe Costanza
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Sarah Sciuto
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | | | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Units of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
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25
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Jesus-Ribeiro J, Pires LM, Melo JD, Ribeiro IP, Rebelo O, Sales F, Freire A, Melo JB. Genomic and Epigenetic Advances in Focal Cortical Dysplasia Types I and II: A Scoping Review. Front Neurosci 2021; 14:580357. [PMID: 33551717 PMCID: PMC7862327 DOI: 10.3389/fnins.2020.580357] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 12/14/2020] [Indexed: 12/19/2022] Open
Abstract
Introduction: Focal cortical dysplasias (FCDs) are a group of malformations of cortical development that constitute a common cause of drug-resistant epilepsy, often subjected to neurosurgery, with a suboptimal long-term outcome. The past few years have witnessed a dramatic leap in our understanding of the molecular basis of FCD. This study aimed to provide an updated review on the genomic and epigenetic advances underlying FCD etiology, to understand a genotype-phenotype correlation and identify priorities to lead future translational research. Methods: A scoping review of the literature was conducted, according to previously described methods. A comprehensive search strategy was applied in PubMed, Embase, and Web of Science from inception to 07 May 2020. References were screened based on title and abstract, and posteriorly full-text articles were assessed for inclusion according to eligibility criteria. Studies with novel gene variants or epigenetic regulatory mechanisms in patients that underwent epilepsy surgery, with histopathological diagnosis of FCD type I or II according to Palmini's or the ILAE classification system, were included. Data were extracted and summarized for an overview of evidence. Results: Of 1,156 candidate papers, 39 met the study criteria and were included in this review. The advent of next-generation sequencing enabled the detection in resected FCD tissue of low-level brain somatic mutations that occurred during embryonic corticogenesis. The mammalian target of rapamycin (mTOR) signaling pathway, involved in neuronal growth and migration, is the key player in the pathogenesis of FCD II. Somatic gain-of-function variants in MTOR and its activators as well as germline, somatic, and second-hit mosaic loss-of-function variants in its related repressors have been reported. However, the genetic background of FCD type I remains elusive, with a pleomorphic repertoire of genes affected. DNA methylation and microRNAs were the two epigenetic mechanisms that proved to have a functional role in FCD and may represent molecular biomarkers. Conclusion: Further research into the possible pathogenic causes of both FCD subtypes is required, incorporating single-cell DNA/RNA sequencing as well as methylome and proteomic analysis. The collected data call for an integrated clinicopathologic and molecular genetic diagnosis in current practice not only to improve diagnostic accuracy but also to guide the development of future targeted treatments.
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Affiliation(s)
- Joana Jesus-Ribeiro
- Epilepsy and Sleep Monitoring Unit, Neurology Department, Coimbra University Hospital Center, Coimbra, Portugal.,iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Luís Miguel Pires
- iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Laboratory of Cytogenetics and Genomics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | | | - Ilda Patrícia Ribeiro
- iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Laboratory of Cytogenetics and Genomics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Olinda Rebelo
- Neuropathology Laboratory, Neurology Department, Coimbra University Hospital Center, Coimbra, Portugal
| | - Francisco Sales
- Epilepsy and Sleep Monitoring Unit, Neurology Department, Coimbra University Hospital Center, Coimbra, Portugal
| | - António Freire
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Joana Barbosa Melo
- iCBR/CIMAGO, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Laboratory of Cytogenetics and Genomics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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26
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Benova B, Sanders MWCB, Uhrova-Meszarosova A, Belohlavkova A, Hermanovska B, Novak V, Stanek D, Vlckova M, Zamecnik J, Aronica E, Braun KPJ, Koeleman BPC, Jansen FE, Krsek P. GATOR1-related focal cortical dysplasia in epilepsy surgery patients and their families: A possible gradient in severity? Eur J Paediatr Neurol 2021; 30:88-96. [PMID: 33461085 DOI: 10.1016/j.ejpn.2020.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/16/2020] [Accepted: 12/04/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND Variants of GATOR1-genes represent a recognised cause of focal cortical dysplasia (FCD), the most common structural aetiology in paediatric drug-resistant focal epilepsy. Reports on familial cases of GATOR1-associated FCD are limited, especially with respect to epilepsy surgery outcomes. METHODS We present phenotypical manifestations of four unrelated patients with drug-resistant focal epilepsy, FCD and a first-degree relative with epilepsy. All patients underwent targeted gene panel sequencing as a part of the presurgical work up. Literature search was performed to compare our findings to previously published cases. RESULTS The children (probands) had a more severe phenotype than their parents, including drug-resistant epilepsy and developmental delay, and they failed to achieve seizure freedom post-surgically. All patients had histopathologically confirmed FCD (types IIa, IIb, Ia). In Patient 1 and her affected father, we detected a known pathogenic NPRL2 variant. In patients 2 and 3 and their affected parents, we found novel likely pathogenic germline DEPDC5 variants. In family 4, we detected a novel variant in NPRL3. We identified 15 additional cases who underwent epilepsy surgery for GATOR1-associated FCD, with a positive family history of epilepsy in the literature; in 8/13 tested, the variant was inherited from an asymptomatic parent. CONCLUSION The presented cases displayed a severity gradient in phenotype with children more severely affected than the parents. Although patients with GATOR1-associated FCD are considered good surgical candidates, post-surgical seizure outcome was poor in our familial cases, suggesting that accurate identification of the epileptogenic zone may be more challenging in this subgroup of patients.
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Affiliation(s)
- Barbora Benova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic; Neurogenetics Laboratory of the Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, Prague, 15006, Czech Republic.
| | - Maurits W C B Sanders
- Department of Child Neurology, Brain Center University Medical Center Utrecht, the Netherlands.
| | - Anna Uhrova-Meszarosova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic; Neurogenetics Laboratory of the Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, Prague, 15006, Czech Republic.
| | - Anezka Belohlavkova
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Barbora Hermanovska
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Vilem Novak
- Department of Paediatric Neurology, Ostrava Faculty Hospital, 17. Listopadu 1790, 708 00, Ostrava-Poruba, Czech Republic.
| | - David Stanek
- Neurogenetics Laboratory of the Department of Paediatric Neurology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, Prague, 15006, Czech Republic.
| | - Marketa Vlckova
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Josef Zamecnik
- Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic.
| | - Eleonora Aronica
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam, Meibergdreef 9, 1105, AZ Amsterdam, the Netherlands; Stichting Epilepsie Instellingen Nederland (SEIN), Achterweg 2, 2103, SW, Heemstede, the Netherlands.
| | - Kees P J Braun
- Department of Child Neurology, Brain Center University Medical Center Utrecht, the Netherlands.
| | - Bobby P C Koeleman
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands.
| | - Floor E Jansen
- Department of Child Neurology, Brain Center University Medical Center Utrecht, the Netherlands.
| | - Pavel Krsek
- Department of Paediatric Neurology, Motol Epilepsy Center, 2nd Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 15006, Prague, Czech Republic.
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Klofas LK, Short BP, Snow JP, Sinnaeve J, Rushing GV, Westlake G, Weinstein W, Ihrie RA, Ess KC, Carson RP. DEPDC5 haploinsufficiency drives increased mTORC1 signaling and abnormal morphology in human iPSC-derived cortical neurons. Neurobiol Dis 2020; 143:104975. [PMID: 32574724 PMCID: PMC7462127 DOI: 10.1016/j.nbd.2020.104975] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 05/21/2020] [Accepted: 06/13/2020] [Indexed: 01/21/2023] Open
Abstract
Mutations in the DEPDC5 gene can cause epilepsy, including forms with and without brain malformations. The goal of this study was to investigate the contribution of DEPDC5 gene dosage to the underlying neuropathology of DEPDC5-related epilepsies. We generated induced pluripotent stem cells (iPSCs) from epilepsy patients harboring heterozygous loss of function mutations in DEPDC5. Patient iPSCs displayed increases in both phosphorylation of ribosomal protein S6 and proliferation rate, consistent with elevated mTORC1 activation. In line with these findings, we observed increased soma size in patient iPSC-derived cortical neurons that was rescued with rapamycin treatment. These data indicate that human cells heterozygous for DEPDC5 loss-of-function mutations are haploinsufficient for control of mTORC1 signaling. Our findings suggest that human pathology differs from mouse models of DEPDC5-related epilepsies, which do not show consistent phenotypic differences in heterozygous neurons, and support the need for human-based models to affirm and augment the findings from animal models of DEPDC5-related epilepsy.
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Affiliation(s)
- Lindsay K Klofas
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - Brittany P Short
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John P Snow
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Justine Sinnaeve
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | | | - Grant Westlake
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Will Weinstein
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Rebecca A Ihrie
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kevin C Ess
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Robert P Carson
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA.
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28
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Lee WS, Stephenson SEM, Pope K, Gillies G, Maixner W, Macdonald-Laurs E, MacGregor D, D'Arcy C, Jackson G, Harvey AS, Leventer RJ, Lockhart PJ. Genetic characterization identifies bottom-of-sulcus dysplasia as an mTORopathy. Neurology 2020; 95:e2542-e2551. [PMID: 32847954 DOI: 10.1212/wnl.0000000000010670] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 06/03/2020] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE To determine the genetic basis of bottom-of-sulcus dysplasia (BOSD), which is a highly focal and epileptogenic cortical malformation in which the imaging, electrophysiologic, and pathologic abnormalities are maximal at the bottom of sulcus, tapering to a normal gyral crown. METHODS Targeted panel deep sequencing (>500×) was performed on paired blood and brain-derived genomic DNA from 20 operated patients with drug-resistant focal epilepsy and BOSD. Histopathology was assessed using immunohistochemistry. RESULTS Brain-specific pathogenic somatic variants were found in 6 patients and heterozygous pathogenic germline variants were found in 2. Somatic variants were identified in MTOR and germline variants were identified in DEPDC5 and NPRL3. Two patients with somatic MTOR variants showed a mutation gradient, with higher mutation load at the bottom of sulcus compared to the gyral crown. Immunohistochemistry revealed an abundance of dysmorphic neurons and balloon cells in the bottom of sulcus but not in the gyral crown or adjacent gyri. CONCLUSIONS BOSD is associated with mTOR pathway dysregulation and shares common genetic etiologies and pathogenic mechanisms with other forms of focal and hemispheric cortical dysplasia, suggesting these disorders are on a genetic continuum.
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Affiliation(s)
- Wei Shern Lee
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Sarah E M Stephenson
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Kate Pope
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Greta Gillies
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Wirginia Maixner
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Emma Macdonald-Laurs
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Duncan MacGregor
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Colleen D'Arcy
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Graeme Jackson
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - A Simon Harvey
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Richard J Leventer
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia
| | - Paul J Lockhart
- From the Bruce Lefroy Centre (W.S.L., S.E.M.S., K.P., G.G., P.J.L.), Murdoch Children's Research Institute (W.M., A.S.H., R.J.L.); Department of Paediatrics (W.S.L., S.E.M.S., W.M., E.M.-L., A.S.H., R.J.L., P.J.L.), The University of Melbourne; Departments of Neurosurgery (W.M.), Neurology (E.M.-L., A.S.H., R.J.L.), and Anatomical Pathology (D.M., C.D.), The Royal Children's Hospital, Parkville; and Melbourne Brain Centre (G.J.), The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia.
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Liu L, Chen ZR, Xu HQ, Liu DT, Mao Y, Liu HK, Liu XR, Zhou P, Lin SM, Li B, He N, Su T, Zhai QX, Meng H, Liao WP, Yi YH. DEPDC5 Variants Associated Malformations of Cortical Development and Focal Epilepsy With Febrile Seizure Plus/Febrile Seizures: The Role of Molecular Sub-Regional Effect. Front Neurosci 2020; 14:821. [PMID: 32848577 PMCID: PMC7432260 DOI: 10.3389/fnins.2020.00821] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 07/14/2020] [Indexed: 11/23/2022] Open
Abstract
To explore the phenotype spectrum of DEPDC5 variants and the possible mechanisms underlying phenotypical variation, we performed targeted next-generation sequencing in 305 patients with focal epilepsies and 91 patients with generalized epilepsies. Protein modeling was performed to predict the effects of missense mutations. All previously reported epilepsy-related DEPDC5 variants were reviewed. The genotype–phenotype correlations with molecular sub-regional implications were analyzed. We identified a homozygous DEPDC5 mutation (p.Pro1031His) in a case with focal cortical dysplasia and eight heterozygous mutations in 11 families with mild focal epilepsies, including 13 patients in eight families with focal epilepsy with febrile seizures plus/febrile seizures (FEFS + /FS). The mutations included one termination codon mutation (p.Ser1601_Ter1604del_ext133), three truncating mutations (p.Val151Serfs∗27, p.Arg239∗, and p.Arg838∗), and four missense mutations (p.Tyr7Cys, p.Tyr836Cys, p.Pro1031His, and p.Gly1545Ser) that were predicted to affect hydrogen bonds and protein stability. Analysis on epilepsy-related DEPDC5 variants revealed that malformations of cortical development (MCDs) had a tendency of higher frequency of null mutations than those without MCD. MCD-associated heterozygous missense mutations were clustered in structural axis for binding arrangement (SABA) domain and close to the binding sites to NPRL2/NPRL3 complex, whereas those associated with FEFS + /FS were a distance away from the binding sites. Evidence from four aspects and one possible evidence from sub-regional implication suggested MCD and FEFS + /FS as phenotypes of DEPDC5 variants. This study suggested that the phenotypes of DEPDC5 variants vary from mild FEFS + /FS to severe MCD. Heterozygous DEPDC5 mutations are generally less pathogenic and commonly associated with mild phenotypes. Bi-allelic mutations and second hit of somatic mutations, together with the genotype–phenotype correlation and sub-regional implication of DEPDC5 variants, explain severe phenotypes.
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Affiliation(s)
- Liu Liu
- Institute of Neuroscience, 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, China.,Department of Neurology, Xiaoshan First People's Hospital, Hangzhou, China
| | - Zi-Rong Chen
- Institute of Neuroscience, 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, China.,Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Hai-Qing Xu
- Department of Neurology, Xuzhou Central Hospital, Affiliated Hospital of Southeast University, Xuzhou, China
| | - De-Tian Liu
- Institute of Neuroscience, 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, China
| | | | | | - Xiao-Rong Liu
- Institute of Neuroscience, 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, China
| | - Peng Zhou
- Institute of Neuroscience, 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, China
| | - Si-Mei Lin
- Institute of Neuroscience, 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, China
| | - Bin Li
- Institute of Neuroscience, 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, China
| | - Na He
- Institute of Neuroscience, 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, China
| | - Tao Su
- Institute of Neuroscience, 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, China
| | - Qiong-Xiang Zhai
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Heng Meng
- Department of Neurology of the First Affiliated Hospital of Jinan University and Clinical Neuroscience Institute of Jinan University, Guangzhou, China
| | - Wei-Ping Liao
- Institute of Neuroscience, 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, China
| | - Yong-Hong Yi
- Institute of Neuroscience, 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, China
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30
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Gawel K, Langlois M, Martins T, van der Ent W, Tiraboschi E, Jacmin M, Crawford AD, Esguerra CV. Seizing the moment: Zebrafish epilepsy models. Neurosci Biobehav Rev 2020; 116:1-20. [PMID: 32544542 DOI: 10.1016/j.neubiorev.2020.06.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/20/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022]
Abstract
Zebrafish are now widely accepted as a valuable animal model for a number of different central nervous system (CNS) diseases. They are suitable both for elucidating the origin of these disorders and the sequence of events culminating in their onset, and for use as a high-throughput in vivo drug screening platform. The availability of powerful and effective techniques for genome manipulation allows the rapid modelling of different genetic epilepsies and of conditions with seizures as a core symptom. With this review, we seek to summarize the current knowledge about existing epilepsy/seizures models in zebrafish (both pharmacological and genetic) and compare them with equivalent rodent and human studies. New findings obtained from the zebrafish models are highlighted. We believe that this comprehensive review will highlight the value of zebrafish as a model for investigating different aspects of epilepsy and will help researchers to use these models to their full extent.
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Affiliation(s)
- Kinga Gawel
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego St. 8b, 20-090, Lublin, Poland
| | | | - Teresa Martins
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Wietske van der Ent
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway
| | - Ettore Tiraboschi
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway; Neurophysics Group, Center for Mind/Brain Sciences, University of Trento, Piazza Manifattura 1, Building 14, 38068, Rovereto, TN, Italy
| | - Maxime Jacmin
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg
| | - Alexander D Crawford
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belval, Luxembourg; Faculty of Veterinary Medicine, Norwegian University of Life Sciences (NMBU), Oslo, Norway
| | - Camila V Esguerra
- Chemical Neuroscience Group, Centre for Molecular Medicine Norway (NCMM), University of Oslo, Gaustadalléen 21, Forskningsparken, 0349, Oslo, Norway.
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31
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Yuskaitis CJ, Rossitto LA, Gurnani S, Bainbridge E, Poduri A, Sahin M. Chronic mTORC1 inhibition rescues behavioral and biochemical deficits resulting from neuronal Depdc5 loss in mice. Hum Mol Genet 2020; 28:2952-2964. [PMID: 31174205 DOI: 10.1093/hmg/ddz123] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/31/2019] [Accepted: 06/04/2019] [Indexed: 01/05/2023] Open
Abstract
DEPDC5 is now recognized as one of the genes most often implicated in familial/inherited focal epilepsy and brain malformations. Individuals with pathogenic variants in DEPDC5 are at risk for epilepsy, associated neuropsychiatric comorbidities and sudden unexplained death in epilepsy. Depdc5flox/flox-Syn1Cre (Depdc5cc+) neuronal-specific Depdc5 knockout mice exhibit seizures and neuronal mTORC1 hyperactivation. It is not known if Depdc5cc+ mice have a hyperactivity/anxiety phenotype, die early from terminal seizures or whether mTOR inhibitors rescue DEPDC5-related seizures and associated comorbidities. Herein, we report that Depdc5cc+ mice were hyperactive in open-field testing but did not display anxiety-like behaviors on the elevated-plus maze. Unlike many other mTOR-related models, Depdc5cc+ mice had minimal epileptiform activity and rare seizures prior to seizure-induced death, as confirmed by video-EEG monitoring. Treatment with the mTORC1 inhibitor rapamycin starting after 3 weeks of age significantly prolonged the survival of Depdc5cc+ mice and partially rescued the behavioral hyperactivity. Rapamycin decreased the enlarged brain size of Depdc5cc+ mice with corresponding decrease in neuronal soma size. Loss of Depdc5 led to a decrease in the other GATOR1 protein levels (NPRL2 and NPRL3). Rapamycin failed to rescue GATOR1 protein levels but rather rescued downstream mTORC1 hyperactivity as measured by phosphorylation of S6. Collectively, our data provide the first evidence of behavioral alterations in mice with Depdc5 loss and support mTOR inhibition as a rational therapeutic strategy for DEPDC5-related epilepsy in humans.
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Affiliation(s)
- Christopher J Yuskaitis
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Leigh-Ana Rossitto
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Sarika Gurnani
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Elizabeth Bainbridge
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Annapurna Poduri
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Mustafa Sahin
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA
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32
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Garcia CAB, Carvalho SCS, Yang X, Ball LL, George RD, James KN, Stanley V, Breuss MW, Thomé U, Santos MV, Saggioro FP, Neder Serafini L, Silva WA, Gleeson JG, Machado HR. mTOR pathway somatic variants and the molecular pathogenesis of hemimegalencephaly. Epilepsia Open 2020; 5:97-106. [PMID: 32140648 PMCID: PMC7049797 DOI: 10.1002/epi4.12377] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/16/2019] [Accepted: 01/02/2020] [Indexed: 12/28/2022] Open
Abstract
Objectives Recently, defects in the protein kinase mTOR (mammalian target of rapamycin) and its associated pathway have been correlated with hemimegalencephaly (HME). mTOR acts as a central regulator of important physiological cellular functions such as growth and proliferation, metabolism, autophagy, death, and survival. This study was aimed at identifying specific variants in mTOR signaling pathway genes in patients diagnosed with HME. Methods Using amplicon and whole exome sequencing (WES) of resected brain and paired blood samples from five HME patients, we were able to identify pathogenic mosaic variants in the mTOR pathway genes MTOR, PIK3CA, and DEPDC5. Results These results strengthen the hypothesis that somatic variants in PI3K-Akt-mTOR pathway genes contribute to HME. We also describe one patient presenting with a pathogenic variant on DEPDC5 gene, which reinforces the role of DEPDC5 on cortical structural changes due to mTORC1 hyperactivation. These findings also provide insights into when in brain development these variants occurred. An early developmental variant is expected to affect a larger number of cells and to result in a larger malformation, whereas the same variant occurring later in development would cause a minor malformation. Significance In the future, numerous somatic variants in known or new genes will undoubtedly be revealed in resected brain samples, making it possible to draw correlations between genotypes and phenotypes and allow for a genetic clinical diagnosis that may help to predict a given patient's outcome.
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Affiliation(s)
- Camila A B Garcia
- Department of Surgery and Anatomy Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Simone C S Carvalho
- Department of Genetics Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Xiaoxu Yang
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Laurel L Ball
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Renee D George
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Kiely N James
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Valentina Stanley
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Martin W Breuss
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Ursula Thomé
- Department of Neurosciences and Behavioral Sciences Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Marcelo V Santos
- Department of Surgery and Anatomy Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
| | - Fabiano P Saggioro
- Department of Pathology Ribeirão Preto School of Medicine University of São Paulo USP Ribeirao Preto SP Brazil
| | - Luciano Neder Serafini
- Department of Pathology Ribeirão Preto School of Medicine University of São Paulo USP Ribeirao Preto SP Brazil
| | - Wilson A Silva
- Department of Genetics Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil.,Center for Medical Genomics University Hospital of Ribeirão Preto Medical School (USP) Ribeirao Preto SP Brazil
| | - Joseph G Gleeson
- Laboratory for Pediatric Brain Disease Howard Hughes Medical Institute Department of Neurosciences University of California San Diego, La Jolla CA USA
| | - Hélio R Machado
- Department of Surgery and Anatomy Ribeirão Preto Medical School University of São Paulo (USP) Ribeirao Preto SP Brazil
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33
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Hillmann P, Fabbro D. PI3K/mTOR Pathway Inhibition: Opportunities in Oncology and Rare Genetic Diseases. Int J Mol Sci 2019; 20:E5792. [PMID: 31752127 PMCID: PMC6888641 DOI: 10.3390/ijms20225792] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/04/2019] [Accepted: 11/12/2019] [Indexed: 12/17/2022] Open
Abstract
The phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway has been implicated as a cancer target. Big pharma players and small companies have been developing small molecule inhibitors of PI3K and/or mTOR since the 1990s. Although four inhibitors have been approved, many open questions regarding tolerability, patient selection, sensitivity markers, development of resistances, and toxicological challenges still need to be addressed. Besides clear oncological indications, PI3K and mTOR inhibitors have been suggested for treating a plethora of different diseases. In particular, genetically induced PI3K/mTOR pathway activation causes rare disorders, known as overgrowth syndromes, like PTEN (phosphatase and tensin homolog) hamartomas, tuberous sclerosis complex (TSC), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-related overgrowth spectrum (PROS), and activated PI3-Kinase delta syndrome (PI3KCD, APDS). Some of those disorders likeTSC or hemimegalencephaly, which are one of the PROS disorders, also belong to a group of diseases called mTORopathies. This group of syndromes presents with additional neurological manifestations associated with epilepsy and other neuropsychiatric symptoms induced by neuronal mTOR pathway hyperactivation. While PI3K and mTOR inhibitors have been and still are intensively tested in oncology indications, their use in genetically defined syndromes and mTORopathies appear to be promising avenues for a pharmacological intervention.
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Affiliation(s)
| | - Doriano Fabbro
- PIQUR Therapeutics, Hochbergerstrasse 60C, 4057 Basel, Switzerland
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34
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Iffland PH, Carson V, Bordey A, Crino PB. GATORopathies: The role of amino acid regulatory gene mutations in epilepsy and cortical malformations. Epilepsia 2019; 60:2163-2173. [PMID: 31625153 PMCID: PMC7155771 DOI: 10.1111/epi.16370] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/20/2019] [Accepted: 09/20/2019] [Indexed: 12/11/2022]
Abstract
The mechanistic target of rapamycin (mTOR) pathway has been implicated in a growing number of malformations of cortical development (MCD) associated with intractable epilepsy. Mutations in single genes encoding mTOR pathway regulatory proteins have been linked to MCD such as focal cortical dysplasia (FCD) types IIa and IIb, hemimegalencephaly (HME), and megalencephaly. Recent studies have demonstrated that the GATOR1 protein complex, comprised of DEPDC5, NPRL3, and NPRL2, plays a pivotal role in regulating mTOR signaling in response to cellular amino acid levels and that mutations in DEPDC5, NPRL3, or NPRL2 are linked to FCD, HME, and seizures. Histopathological analysis of FCD and HME tissue specimens resected from individuals harboring DEPDC5, NPRL3, or NPRL2 gene mutations reveals hyperactivation of mTOR pathway signaling. Family pedigrees carrying mutations in either DEPDC5 or NPRL3 share clinical phenotypes of epilepsy and MCD, as well as intellectual and neuropsychiatric disabilities. Interestingly, some individuals with seizures associated with DEPDC5, NPRL3, or NPRL2 variants exhibit normal brain imaging suggesting either occult MCD or a role for these genes in non-lesional neocortical epilepsy. Mouse models resulting from knockdown or knockout of either Depdc5 or Nprl3 exhibit altered cortical lamination, neuronal dysmorphogenesis, and enhanced neuronal excitability as reported in models resulting from direct mTOR activation through expression of its canonical activator RHEB. The role of the GATOR1 proteins in regulating mTOR signaling suggest plausible options for mTOR inhibition in the treatment of epilepsy associated with mutations in DEPDC5, NPRL3, or NPRL2.
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Affiliation(s)
- Philip H. Iffland
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Vincent Carson
- The Clinic for Special Children, Strasburg, Pennsylvania
| | - Angelique Bordey
- Department of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut
| | - Peter B. Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland
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35
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Dawson RE, Nieto Guil AF, Robertson LJ, Piltz SG, Hughes JN, Thomas PQ. Functional screening of GATOR1 complex variants reveals a role for mTORC1 deregulation in FCD and focal epilepsy. Neurobiol Dis 2019; 134:104640. [PMID: 31639411 DOI: 10.1016/j.nbd.2019.104640] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/07/2019] [Accepted: 10/13/2019] [Indexed: 12/20/2022] Open
Abstract
Mutations in the GAP activity toward RAGs 1 (GATOR1) complex genes (DEPDC5, NPRL2 and NPRL3) have been associated with focal epilepsy and focal cortical dysplasia (FCD). GATOR1 functions as an inhibitor of the mTORC1 signalling pathway, indicating that the downstream effects of mTORC1 deregulation underpin the disease. However, the vast majority of putative disease-causing variants have not been functionally assessed for mTORC1 repression activity. Here, we develop a novel in vitro functional assay that enables rapid assessment of GATOR1-gene variants. Surprisingly, of the 17 variants tested, we show that only six showed significantly impaired mTORC1 inhibition. To further investigate variant function in vivo, we generated a conditional Depdc5 mouse which modelled a 'second-hit' mechanism of disease. Generation of Depdc5 null 'clones' in the embryonic brain resulted in mTORC1 hyperactivity and modelled epilepsy and FCD symptoms including large dysmorphic neurons, defective migration and lower seizure thresholds. Using this model, we validated DEPDC5 variant F164del to be loss-of-function. We also show that Q542P is not functionally compromised in vivo, consistent with our in vitro findings. Overall, our data show that mTORC1 deregulation is the central pathological mechanism for GATOR1 variants and also indicates that a significant proportion of putative disease variants are pathologically inert, highlighting the importance of GATOR1 variant functional assessment.
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Affiliation(s)
- Ruby E Dawson
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Alvaro F Nieto Guil
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Louise J Robertson
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Sandra G Piltz
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - James N Hughes
- School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia.
| | - Paul Q Thomas
- School of Medicine, University of Adelaide, Adelaide, SA 5005, Australia; Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia; Precision Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA 5000, Australia.
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Bisulli F, Licchetta L, Tinuper P. Sleep related hyper motor epilepsy (SHE): a unique syndrome with heterogeneous genetic etiologies. SLEEP SCIENCE AND PRACTICE 2019. [DOI: 10.1186/s41606-019-0035-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Benova B, Jacques TS. Genotype-phenotype correlations in focal malformations of cortical development: a pathway to integrated pathological diagnosis in epilepsy surgery. Brain Pathol 2019; 29:473-484. [PMID: 30485578 PMCID: PMC8028510 DOI: 10.1111/bpa.12686] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 11/20/2018] [Indexed: 12/18/2022] Open
Abstract
Malformations of cortical development (MCD) comprise a broad spectrum of developmental brain abnormalities. Patients presenting with MCDs often suffer from drug-resistant focal epilepsy, and some become candidates for epilepsy surgery. Their likelihood of achieving freedom from seizures, however, remains uncertain, and depends in a major part on the underlying pathology. Tissue samples obtained in epilepsy surgery form the basis of definite histopathological diagnosis; however, new molecular genetic methods have not yet been implemented in diagnostic processes for MCD cases. Furthermore, it has not been completely understood how the underlying pathology affects patients' outcomes after epilepsy surgery. We performed a systematic literature review of studies describing both histopathological and molecular genetic findings in MCD, along with studies on epilepsy surgery outcomes. We aimed to correlate the genetic causes with the underlying morphological abnormalities in focal cortical malformations and to stress the importance of the underlying biology for patient management and counseling. From the summarized findings of multiple authors, it is obvious that MCD may have a diverse genetic background despite a similar or even identical histopathological picture. Even though most of their molecular genetic findings converge on various levels of the PI3K/AKT/mTOR pathway, the exact mechanisms underlying MCD formation have not yet been completely described or indeed how this pathway generates a diverse range of histological abnormalities. Based on our findings, we therefore propose that all patients diagnosed and operated for drug-resistant epilepsy should have an integrated molecular and pathological diagnosis similar to the current practice in brain tumor diagnostic processes that might lead to more accurate diagnosis and effective stratification of patients undergoing epilepsy surgery.
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Affiliation(s)
- Barbora Benova
- 2nd Faculty of Medicine, Department of Paediatric NeurologyCharles University and Motol University HospitalPragueCzech Republic
- 2nd Faculty of MedicineCharles UniversityPragueCzech Republic
- Developmental Biology and Cancer ProgrammeUCL GOS Institute of Child HealthLondonUK
| | - Thomas S. Jacques
- Developmental Biology and Cancer ProgrammeUCL GOS Institute of Child HealthLondonUK
- Department of HistopathologyGreat Ormond Street Hospital for Children NHS Foundation TrustLondonUK
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Zhang L, Huang T, Teaw S, Bordey A. Hypervascularization in mTOR-dependent focal and global cortical malformations displays differential rapamycin sensitivity. Epilepsia 2019; 60:1255-1265. [PMID: 31125447 DOI: 10.1111/epi.15969] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 04/26/2019] [Accepted: 04/26/2019] [Indexed: 01/16/2023]
Abstract
OBJECTIVES Patients with mammalian target of rapamycin (mTOR)-dependent malformations of cortical development (MCDs) associated with seizures display hyperperfusion and increased vessel density of the dysmorphic cortical tissue. Some studies have suggested that the vascular defect occurred independently of seizures. Here, we further examined whether hypervascularization occurs in animal models of global and focal MCD with and without seizures, and whether it is sensitive to the mTOR blocker, rapamycin, that is approved for epilepsy treatment in tuberous sclerosis complex. METHODS We used two experimental models of mTOR-dependent MCD consisting of conditional transgenic mice containing Tsc1null cells in the forebrain generating a global malformation associated with seizures and of wild-type mice containing a focal malformation in the somatosensory cortex generated by in utero electroporation (IUE) that does not lead to seizures. Alterations in blood vessels and the effects of a 2-week-long rapamycin treatment on these phenotypes were assessed in juvenile mice. RESULTS Blood vessels in both the focal and global MCDs of postnatal day 14 mice displayed significant increase in vessel density, branching index, total vessel length, and decreased tissue lacunarity. In addition, rapamycin treatment (0.5 mg/kg, every 2 days) partially rescued vessel abnormalities in the focal MCD model, but it did not ameliorate the vessel abnormalities in the global MCD model that required higher rapamycin dosage for a partial rescue. SIGNIFICANCE Here, we identified hypervascularization in mTOR-dependent MCD in the absence of seizures in young mice, suggesting that increased angiogenesis occurs during development in parallel to alterations in corticogenesis. In addition, a predictive functional outcome is that dysplastic neurons forming MCD will have better access to oxygen and metabolic supplies via their closer proximity to blood vessels. Finally, the difference in rapamycin sensitivity between a focal and global MCD suggest that rapamycin treatment will need to be titrated to match the type of MCD.
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Affiliation(s)
- Longbo Zhang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
- Departments of Neurosurgery and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut
| | - Tianxiang Huang
- Department of Neurosurgery, Xiangya Hospital, Central South University, Changsha, China
- Departments of Neurosurgery and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut
| | - Shannon Teaw
- Departments of Neurosurgery and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut
| | - Angélique Bordey
- Departments of Neurosurgery and Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut
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Kim JK, Lee JH. Mechanistic Target of Rapamycin Pathway in Epileptic Disorders. J Korean Neurosurg Soc 2019; 62:272-287. [PMID: 31085953 PMCID: PMC6514310 DOI: 10.3340/jkns.2019.0027] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 03/12/2019] [Indexed: 12/19/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) pathway coordinates the metabolic activity of eukaryotic cells through environmental signals, including nutrients, energy, growth factors, and oxygen. In the nervous system, the mTOR pathway regulates fundamental biological processes associated with neural development and neurodegeneration. Intriguingly, genes that constitute the mTOR pathway have been found to be germline and somatic mutation from patients with various epileptic disorders. Hyperactivation of the mTOR pathway due to said mutations has garnered increasing attention as culprits of these conditions : somatic mutations, in particular, in epileptic foci have recently been identified as a major genetic cause of intractable focal epilepsy, such as focal cortical dysplasia. Meanwhile, epilepsy models with aberrant activation of the mTOR pathway have helped elucidate the role of the mTOR pathway in epileptogenesis, and evidence from epilepsy models of human mutations recapitulating the features of epileptic patients has indicated that mTOR inhibitors may be of use in treating epilepsy associated with mutations in mTOR pathway genes. Here, we review recent advances in the molecular and genetic understanding of mTOR signaling in epileptic disorders. In particular, we focus on the development of and limitations to therapies targeting the mTOR pathway to treat epileptic seizures. We also discuss future perspectives on mTOR inhibition therapies and special diagnostic methods for intractable epilepsies caused by brain somatic mutations.
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Affiliation(s)
- Jang Keun Kim
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Jeong Ho Lee
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea.,Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
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40
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Mühlebner A, Bongaarts A, Sarnat HB, Scholl T, Aronica E. New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives. J Anat 2019; 235:521-542. [PMID: 30901081 DOI: 10.1111/joa.12956] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2019] [Indexed: 12/20/2022] Open
Abstract
In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.
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Affiliation(s)
- A Mühlebner
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - A Bongaarts
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H B Sarnat
- Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute (Owerko Centre), Calgary, AB, Canada
| | - T Scholl
- Department of Paediatric and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - E Aronica
- Department of Neuropathology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Amsterdam, The Netherlands
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41
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Pippucci T, Licchetta L, Baldassari S, Marconi C, De Luise M, Myers C, Nardi E, Provini F, Cameli C, Minardi R, Bacchelli E, Giordano L, Crichiutti G, d'Orsi G, Seri M, Gasparre G, Mefford HC, Tinuper P, Bisulli F. Contribution of ultrarare variants in mTOR pathway genes to sporadic focal epilepsies. Ann Clin Transl Neurol 2019; 6:475-485. [PMID: 30911571 PMCID: PMC6414475 DOI: 10.1002/acn3.722] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 12/07/2018] [Accepted: 12/08/2018] [Indexed: 01/16/2023] Open
Abstract
Objective We investigated the contribution to sporadic focal epilepsies (FE) of ultrarare variants in genes coding for the components of complexes regulating mechanistic Target Of Rapamycin (mTOR)complex 1 (mTORC1). Methods We collected genetic data of 121 Italian isolated FE cases and 512 controls by Whole Exome Sequencing (WES) and single-molecule Molecular Inversion Probes (smMIPs) targeting 10 genes of the GATOR1, GATOR2, and TSC complexes. We collapsed "qualifying" variants (ultrarare and predicted to be deleterious or loss of function) across the examined genes and sought to identify their enrichment in cases compared to controls. Results We found eight qualifying variants in cases and nine in controls, demonstrating enrichment in FE patients (P = 0.006; exact unconditional test, one-tailed). Pathogenic variants were identified in DEPDC5 and TSC2, both major genes for Mendelian FE syndromes. Interpretation Our findings support the contribution of ultrarare variants in genes in the mTOR pathway complexes GATOR and TSC to the risk of sporadic FE and a shared genetic basis between rare and common epilepsies. The identification of a monogenic etiology in isolated cases, most typically encountered in clinical practice, may offer to a broader community of patients the perspective of precision therapies directed by the underlying genetic cause.
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Affiliation(s)
- Tommaso Pippucci
- Medical Genetics UnitPolyclinic Sant'Orsola‐Malpighi University HospitalBolognaItaly
| | - Laura Licchetta
- IRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
- Department of Biomedical and Neuromotor Sciences (DIBINEM)University of BolognaBolognaItaly
| | - Sara Baldassari
- Department of Biomedical and Surgical Sciences (DIMEC)University of BolognaBolognaItaly
| | - Caterina Marconi
- Department of Biomedical and Surgical Sciences (DIMEC)University of BolognaBolognaItaly
| | - Monica De Luise
- Department of Biomedical and Surgical Sciences (DIMEC)University of BolognaBolognaItaly
| | - Candace Myers
- Division of Genetic MedicineDepartment of PediatricsUniversity of WashingtonSeattleWashington
| | - Elena Nardi
- Department of Statistical Sciences “Paolo Fortunati”University of BolognaBolognaItaly
| | - Federica Provini
- IRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
- Department of Biomedical and Neuromotor Sciences (DIBINEM)University of BolognaBolognaItaly
| | - Cinzia Cameli
- Department of Pharmacy and BiotechnologyUniversity of BolognaBolognaItaly
| | - Raffaella Minardi
- IRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
- Department of Biomedical and Neuromotor Sciences (DIBINEM)University of BolognaBolognaItaly
| | - Elena Bacchelli
- Department of Pharmacy and BiotechnologyUniversity of BolognaBolognaItaly
| | | | | | - Giuseppe d'Orsi
- Epilepsy CenterClinic of Nervous System DiseasesUniversity of FoggiaRiuniti HospitalFoggiaItaly
| | - Marco Seri
- Medical Genetics UnitPolyclinic Sant'Orsola‐Malpighi University HospitalBolognaItaly
- Department of Biomedical and Surgical Sciences (DIMEC)University of BolognaBolognaItaly
| | - Giuseppe Gasparre
- Department of Biomedical and Surgical Sciences (DIMEC)University of BolognaBolognaItaly
| | - Heather C. Mefford
- Division of Genetic MedicineDepartment of PediatricsUniversity of WashingtonSeattleWashington
| | - Paolo Tinuper
- IRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
- Department of Biomedical and Neuromotor Sciences (DIBINEM)University of BolognaBolognaItaly
| | - Francesca Bisulli
- IRCCS Istituto delle Scienze Neurologiche di BolognaBolognaItaly
- Department of Biomedical and Neuromotor Sciences (DIBINEM)University of BolognaBolognaItaly
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Abstract
PURPOSE OF REVIEW Focal cortical dysplasias (FCDs) represent common cortical malformations that are frequently associated with epilepsy. They have so far not been well understood in terms of their molecular pathogenesis, and with respect to mechanisms of seizure emergence. RECENT FINDINGS Several recent studies have succeeded in making significant advances in understanding the molecular genetics, in particular FCD type II. A second major advance has been the development of novel rodent models of FCDs that replicate a somatic mutation seen in humans, lead to a focal lesion, and recapitulate many phenotypic features of human FCDs. We will discuss these recent advances. SUMMARY These advances promise significant advances in understanding the heterogeneity of FCDs at the molecular genetic level. They also promise a much better understanding of cell-intrinsic and network mechanisms underlying increased seizure susceptibility and altered cognition. Systematic studies utilizing the approaches summarized here promise to lead to specific strategies regarding when and how to treat specific subgroups of FCDs.
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Marsan E, Baulac S. Review: Mechanistic target of rapamycin (mTOR) pathway, focal cortical dysplasia and epilepsy. Neuropathol Appl Neurobiol 2019; 44:6-17. [PMID: 29359340 DOI: 10.1111/nan.12463] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/17/2018] [Indexed: 12/19/2022]
Abstract
Over the last decade, there has been increasing evidence that hyperactivation of the mechanistic target of rapamycin (mTOR) pathway is a hallmark of malformations of cortical development such as focal cortical dysplasia (FCD) or hemimegalencephaly. The mTOR pathway governs protein and lipid synthesis, cell growth and proliferation as well as metabolism and autophagy. The molecular genetic aetiology of mTOR hyperactivation has only been recently clarified. This article will review the current and still evolving genetic advances in the elucidation of the molecular basis of FCD. Activating somatic mutations in the MTOR gene are to date the most frequent mutations found in FCD brain specimens.
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Affiliation(s)
- E Marsan
- Department of Genetics and Cytogenetics, AP-HP, Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Inserm U1127, CNRS UMR 7225, Paris, France
| | - S Baulac
- Department of Genetics and Cytogenetics, AP-HP, Institut du Cerveau et de la Moelle Epinière (ICM) - Hôpital Pitié-Salpêtrière, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Inserm U1127, CNRS UMR 7225, Paris, France
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Juric-Sekhar G, Hevner RF. Malformations of Cerebral Cortex Development: Molecules and Mechanisms. ANNUAL REVIEW OF PATHOLOGY 2019; 14:293-318. [PMID: 30677308 PMCID: PMC6938687 DOI: 10.1146/annurev-pathmechdis-012418-012927] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Malformations of cortical development encompass heterogeneous groups of structural brain anomalies associated with complex neurodevelopmental disorders and diverse genetic and nongenetic etiologies. Recent progress in understanding the genetic basis of brain malformations has been driven by extraordinary advances in DNA sequencing technologies. For example, somatic mosaic mutations that activate mammalian target of rapamycin signaling in cortical progenitor cells during development are now recognized as the cause of hemimegalencephaly and some types of focal cortical dysplasia. In addition, research on brain development has begun to reveal the cellular and molecular bases of cortical gyrification and axon pathway formation, providing better understanding of disorders involving these processes. New neuroimaging techniques with improved resolution have enhanced our ability to characterize subtle malformations, such as those associated with intellectual disability and autism. In this review, we broadly discuss cortical malformations and focus on several for which genetic etiologies have elucidated pathogenesis.
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Affiliation(s)
- Gordana Juric-Sekhar
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington 98195, USA; ,
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195, USA
| | - Robert F Hevner
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington 98195, USA; ,
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195, USA
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington 98105, USA
- Current affiliation: Department of Pathology, University of California, San Diego, California 92093, USA
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Abstract
Epilepsy is one of the most frequent neurological disorders characterized by spontaneous and recurrent seizures. Most seizures last for the lifetime and the patients require long term therapies. However, about 30% of the patients are refractory to antiepileptic drugs. Therefore, the need for newer and more effective therapies is urgent. Focal epilepsies, in which the abnormal electrical discharges occur within neuronal networks limited to one hemisphere, accounts for about 60% of all adult idiopathic epilepsy cases. Recently, mutations of DEPDC5 gene has been reported in wide spectrum of focal epilepsy syndromes. Most epilepsy genes encode ion channel or transmitter receptor, but DEPDC5 has no homology with them. DEPDC5 forms a complex, named GATOR1, together with other focal epilepsy related proteins NPRL2 and NPRL3. GATOR1 inhibits the mTORC1 pathway, regulating multiple cellular processes including cell growth and proliferation. The role of DEPDC5 in neuronal system is becoming clear from recent studies using the animal models. Because DEPDC5 is the most common causative gene in focal epilepsies and different from other epilepsy genes, DEPDC5 will be a key to understand epileptogenesis of various epilepsies, and provide new insight to develop new versatile therapies.
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Affiliation(s)
- Saeko Ishida
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU)
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46
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Baldassari S, Picard F, Verbeek NE, van Kempen M, Brilstra EH, Lesca G, Conti V, Guerrini R, Bisulli F, Licchetta L, Pippucci T, Tinuper P, Hirsch E, de Saint Martin A, Chelly J, Rudolf G, Chipaux M, Ferrand-Sorbets S, Dorfmüller G, Sisodiya S, Balestrini S, Schoeler N, Hernandez-Hernandez L, Krithika S, Oegema R, Hagebeuk E, Gunning B, Deckers C, Berghuis B, Wegner I, Niks E, Jansen FE, Braun K, de Jong D, Rubboli G, Talvik I, Sander V, Uldall P, Jacquemont ML, Nava C, Leguern E, Julia S, Gambardella A, d'Orsi G, Crichiutti G, Faivre L, Darmency V, Benova B, Krsek P, Biraben A, Lebre AS, Jennesson M, Sattar S, Marchal C, Nordli DR, Lindstrom K, Striano P, Lomax LB, Kiss C, Bartolomei F, Lepine AF, Schoonjans AS, Stouffs K, Jansen A, Panagiotakaki E, Ricard-Mousnier B, Thevenon J, de Bellescize J, Catenoix H, Dorn T, Zenker M, Müller-Schlüter K, Brandt C, Krey I, Polster T, Wolff M, Balci M, Rostasy K, Achaz G, Zacher P, Becher T, Cloppenborg T, Yuskaitis CJ, Weckhuysen S, Poduri A, Lemke JR, Møller RS, Baulac S. The landscape of epilepsy-related GATOR1 variants. Genet Med 2018; 21:398-408. [PMID: 30093711 PMCID: PMC6292495 DOI: 10.1038/s41436-018-0060-2] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/02/2018] [Indexed: 01/28/2023] Open
Abstract
Purpose To define the phenotypic and mutational spectrum of epilepsies related to DEPDC5, NPRL2 and NPRL3 genes encoding the GATOR1 complex, a negative regulator of the mTORC1 pathway Methods We analyzed clinical and genetic data of 73 novel probands (familial and sporadic) with epilepsy-related variants in GATOR1-encoding genes and proposed new guidelines for clinical interpretation of GATOR1 variants. Results The GATOR1 seizure phenotype consisted mostly in focal seizures (e.g., hypermotor or frontal lobe seizures in 50%), with a mean age at onset of 4.4 years, often sleep-related and drug-resistant (54%), and associated with focal cortical dysplasia (20%). Infantile spasms were reported in 10% of the probands. Sudden unexpected death in epilepsy (SUDEP) occurred in 10% of the families. Novel classification framework of all 140 epilepsy-related GATOR1 variants (including the variants of this study) revealed that 68% are loss-of-function pathogenic, 14% are likely pathogenic, 15% are variants of uncertain significance and 3% are likely benign. Conclusion Our data emphasize the increasingly important role of GATOR1 genes in the pathogenesis of focal epilepsies (>180 probands to date). The GATOR1 phenotypic spectrum ranges from sporadic early-onset epilepsies with cognitive impairment comorbidities to familial focal epilepsies, and SUDEP.
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Affiliation(s)
- Sara Baldassari
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France.,INSERM, U1127, F-75013, Paris, France.,CNRS, UMR 7225, F-75013, Paris, France.,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Fabienne Picard
- Department of Clinical Neurosciences, University Hospitals and Medical School of Geneva, Geneva, Switzerland
| | - Nienke E Verbeek
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marjan van Kempen
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Eva H Brilstra
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Gaetan Lesca
- Service de Génétique, Hospices Civils de Lyon - GHE; CNRS UMR 5292, INSERM U1028, CNRL, et Université Claude Bernard Lyon 1, GHE, Lyon, France
| | - Valerio Conti
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, A. Meyer Children's Hospital, Florence, Italy
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, A. Meyer Children's Hospital, Florence, Italy
| | - Francesca Bisulli
- IRCCS, Istituto delle Scienze Neurologiche of Bologna; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Laura Licchetta
- IRCCS, Istituto delle Scienze Neurologiche of Bologna; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Tommaso Pippucci
- Medical Genetics Unit, Polyclinic Sant' Orsola-Malpighi University Hospital, Bologna, Italy
| | - Paolo Tinuper
- IRCCS, Istituto delle Scienze Neurologiche of Bologna; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Edouard Hirsch
- Department of Neurology-centre de référence des épilepsies rares, University Hospital of Strasbourg, Strasbourg, France
| | - Anne de Saint Martin
- Department of Pediatrics - centre de référence des épilepsies rares, University Hospital of Strasbourg, Strasbourg, France
| | - Jamel Chelly
- IGBMC, INSERM, CNRS, Strasbourg University, Strasbourg, France
| | | | - Mathilde Chipaux
- Department of Pediatric Neurosurgery, Fondation Rothschild, F-75019, Paris, France
| | | | - Georg Dorfmüller
- Department of Pediatric Neurosurgery, Fondation Rothschild, F-75019, Paris, France
| | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Simona Balestrini
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Natasha Schoeler
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Laura Hernandez-Hernandez
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - S Krithika
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, WC1N 3BG, and Chalfont Centre for Epilepsy, Bucks, UK
| | - Renske Oegema
- Department of Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Eveline Hagebeuk
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Boudewijn Gunning
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Charles Deckers
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Bianca Berghuis
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Ilse Wegner
- Stichting Epilepsie Instellingen Nederland, Zwolle/Heemstede, The Netherlands
| | - Erik Niks
- Leiden University Medical Center, Leiden, The Netherlands
| | - Floor E Jansen
- Department of Child Neurology, Brain Center Rudolf Magnus, University Medical Center, Utrecht, The Netherlands
| | - Kees Braun
- Department of Child Neurology, Brain Center Rudolf Magnus, University Medical Center, Utrecht, The Netherlands
| | - Daniëlle de Jong
- Department of Neurology, Academic Center for Epileptology Kempenhaeghe, Heeze, The Netherlands
| | - Guido Rubboli
- Danish Epilepsy Centre, Dianalund, University of Copenhagen, Copenhagen, Denmark
| | - Inga Talvik
- Department of Neurology and Rehabilitation, Tallinn Children's Hospital, Tallinn, Estonia
| | - Valentin Sander
- Department of Neurology and Rehabilitation, Tallinn Children's Hospital, Tallinn, Estonia
| | | | | | - Caroline Nava
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France.,INSERM, U1127, F-75013, Paris, France.,CNRS, UMR 7225, F-75013, Paris, France.,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Eric Leguern
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France.,INSERM, U1127, F-75013, Paris, France.,CNRS, UMR 7225, F-75013, Paris, France.,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Sophie Julia
- Service de Génétique Médicale, Pavillon Lefebvre, Hôpital Purpan CHU Toulouse, Toulouse, France
| | - Antonio Gambardella
- Institute of Neurology, Department of Medical and Surgical Sciences, University Magna Græcia, Catanzaro, Italy
| | - Giuseppe d'Orsi
- Epilepsy Center, Clinic of Nervous System Diseases, University of Foggia, Riuniti Hospital, Foggia, Italy
| | - Giovanni Crichiutti
- Department of Pediatrics, Institute of Medicine, University Hospital of Udine, Udine, Italy
| | - Laurence Faivre
- Centre de Référence Anomalies du Développement et Syndromes Malformatifs et FHU TRANSLAD, CHU de Dijon et Université de Bourgogne, Dijon, France
| | | | - Barbora Benova
- Department of Paediatric Neurology, Motol University Hospital, 2nd faculty of medicine Charles University, Prague, Czech Republic
| | - Pavel Krsek
- Department of Paediatric Neurology, Motol University Hospital, 2nd faculty of medicine Charles University, Prague, Czech Republic
| | - Arnaud Biraben
- Centre Hospitalier Universitaire de Rennes, F-35000, Rennes, France
| | - Anne-Sophie Lebre
- CHU Reims, Hôpital Maison Blanche, Pôle de Biologie, Service de Génétique, Reims, F-51092, France
| | - Mélanie Jennesson
- CHU Reims, American Memorial Hospital, Service de Pédiatrie, REIMS, F-51092, France
| | - Shifteh Sattar
- Department of Pediatric Neurology, Rady Children's Hospital/University of California, San Diego, California, USA
| | - Cécile Marchal
- Service d'Epileptologie Clinique, CHU de Bordeaux, France
| | - Douglas R Nordli
- Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Kristin Lindstrom
- Division of Genetics and Metabolism, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, "G. Gaslini" Institute, Genova, Italy
| | - Lysa Boissé Lomax
- Department of Medicine, Divisions of Neurology and Respirology, Queen's University, Kingston, Ontario, Canada.,Kingston Health Sciences Centre, Kingston, Ontario, K7L 2V7, Canada
| | - Courtney Kiss
- Kingston Health Sciences Centre, Kingston, Ontario, K7L 2V7, Canada
| | - Fabrice Bartolomei
- Pediatric Neurology Department, Timone Hospital, APHM, Marseille, France
| | | | - An-Sofie Schoonjans
- Department of Pediatric Neurology, Antwerp University Hospital, Edegem, Belgium
| | - Katrien Stouffs
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Neurogenetics Research Group, Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Anna Jansen
- Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel), Neurogenetics Research Group, Laarbeeklaan 101, 1090, Brussels, Belgium
| | - Eleni Panagiotakaki
- Paediatric Clinical Epileptology, Sleep disorders and Functional Neurology, University Hospitals of Lyon (HCL), Lyon, France
| | | | - Julien Thevenon
- Inserm UMR 1231 GAD Team, Genetics of Developmental Anomalies, et FHU-TRANSLAD, CHU/Université de Bourgogne-Franche Comté, Dijon, France
| | - Julitta de Bellescize
- Paediatric Clinical Epileptology, Sleep disorders and Functional Neurology, University Hospitals of Lyon (HCL), Lyon, France
| | - Hélène Catenoix
- Paediatric Clinical Epileptology, Sleep disorders and Functional Neurology, University Hospitals of Lyon (HCL), Lyon, France
| | - Thomas Dorn
- Clinique Bernoise, Crans-, Montana, Switzerland
| | - Martin Zenker
- Institute of Human Genetics, University Hospital, Magdeburg, Germany
| | - Karen Müller-Schlüter
- Epilepsy Center for Children, Brandenburg Medical School, University Hospital, Neuruppin, Germany
| | | | - Ilona Krey
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | | | - Markus Wolff
- Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital, Tübingen, Germany
| | - Meral Balci
- Department of Pediatric Neurology, Children's Hospital Datteln, Witten/Herdecke University, Datteln, Germany
| | - Kevin Rostasy
- Department of Pediatric Neurology, Children's Hospital Datteln, Witten/Herdecke University, Datteln, Germany
| | - Guillaume Achaz
- Institut de Systématique, Evolution, Biodiversité, ISYEB, UMR 7205 CNRS MNHN UPMC EPHE, Paris, France
| | - Pia Zacher
- The Saxon Epilepsy Center Kleinwachau, Radeberg, Germany
| | - Thomas Becher
- Kinderneurologisches Zentrum, Düsseldorf-Gerresheim, Sana Kliniken, Düsseldorf, Germany
| | | | - Christopher J Yuskaitis
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Sarah Weckhuysen
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium
| | - Annapurna Poduri
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, USA.,Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts, USA
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany
| | - Rikke S Møller
- Danish Epilepsy Centre, Dianalund; Institute for Regional Health research, University of Southern Denmark, Odense, Denmark
| | - Stéphanie Baulac
- Sorbonne Université, UPMC Univ Paris 06, UMR S 1127, F-75013, Paris, France. .,INSERM, U1127, F-75013, Paris, France. .,CNRS, UMR 7225, F-75013, Paris, France. .,Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, F-75013, Paris, France. .,Department of Genetics, Assistance Publique des Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, F-75013, Paris, France.
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Myers KA, Johnstone DL, Dyment DA. Epilepsy genetics: Current knowledge, applications, and future directions. Clin Genet 2018; 95:95-111. [PMID: 29992546 DOI: 10.1111/cge.13414] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 07/03/2018] [Accepted: 07/06/2018] [Indexed: 12/12/2022]
Abstract
The rapid pace of disease gene discovery has resulted in tremendous advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, and genomes are now available and have led to higher diagnostic rates and insights into the underlying disease processes. As such, the contribution to the care of patients by medical geneticists, neurogeneticists and genetic counselors are significant; the dysmorphic examination, the necessary pre- and post-test counseling, the selection of the appropriate next-generation sequencing-based test(s), and the interpretation of sequencing results require a care provider to have a comprehensive working knowledge of the strengths and limitations of the available testing technologies. As the underlying mechanisms of the encephalopathies and epilepsies are better understood, there may be opportunities for the development of novel therapies based on an individual's own specific genotype. Drug screening with in vitro and in vivo models of epilepsy can potentially facilitate new treatment strategies. The future of epilepsy genetics will also probably include other-omic approaches such as transcriptomes, metabolomes, and the expanded use of whole genome sequencing to further improve our understanding of epilepsy and provide better care for those with the disease.
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Affiliation(s)
- K A Myers
- Department of Pediatrics, University of McGill, Montreal, Canada.,Research Institute of the McGill University Health Centre, Montreal, Canada
| | - D L Johnstone
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - D A Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada.,Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Canada
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MTOR pathway in focal cortical dysplasia type 2: What do we know? Epilepsy Behav 2018; 85:157-163. [PMID: 29945038 DOI: 10.1016/j.yebeh.2018.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 01/15/2023]
Abstract
Focal cortical dysplasia (FCD) is the most commonly encountered developmental malformation that causes refractory epilepsy. Focal cortical dysplasia type 2 is one of the most usual neuropathological findings in tissues resected therapeutically from patients with drug-resistant epilepsy. Unlike other types of FCD, it is characterized by laminar disorganization and dysplastic neurons, which compromise the organization of the six histologically known layers in the cortex; the morphology and/or cell location can also be altered. A comprehensive review about the pathogenesis of this disease is important because of the necessity to update the results reported over the past years. Here, we present an updated review through Pubmed about the mammalian target of rapamycin (MTOR) pathway in FCD type 2. A wide variety of aspects was covered in 44 articles related to molecular and cellular biology, including experiments in animal and human models. The first publications appeared in 2004, but there is still a lack of studies specifically for one type of FCD. With the advancement of techniques and greater access to molecular and cellular experiments, such as induced pluripotent stem cells (iPSCs) and organoids, it is believed that the trend is increasing the number of publications contributing to the achievement of new discoveries.
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49
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de Calbiac H, Dabacan A, Marsan E, Tostivint H, Devienne G, Ishida S, Leguern E, Baulac S, Muresan RC, Kabashi E, Ciura S. Depdc5 knockdown causes mTOR-dependent motor hyperactivity in zebrafish. Ann Clin Transl Neurol 2018; 5:510-523. [PMID: 29761115 PMCID: PMC5945968 DOI: 10.1002/acn3.542] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 12/18/2022] Open
Abstract
Objective DEPDC5 was identified as a major genetic cause of focal epilepsy with deleterious mutations found in a wide range of inherited forms of focal epilepsy, associated with malformation of cortical development in certain cases. Identification of frameshift, truncation, and deletion mutations implicates haploinsufficiency of DEPDC5 in the etiology of focal epilepsy. DEPDC5 is a component of the GATOR1 complex, acting as a negative regulator of mTOR signaling. Methods Zebrafish represents a vertebrate model suitable for genetic analysis and drug screening in epilepsy-related disorders. In this study, we defined the expression of depdc5 during development and established an epilepsy model with reduced Depdc5 expression. Results Here we report a zebrafish model of Depdc5 loss-of-function that displays a measurable behavioral phenotype, including hyperkinesia, circular swimming, and increased neuronal activity. These phenotypic features persisted throughout embryonic development and were significantly reduced upon treatment with the mTORC1 inhibitor, rapamycin, as well as overexpression of human WT DEPDC5 transcript. No phenotypic rescue was obtained upon expression of epilepsy-associated DEPDC5 mutations (p.Arg487* and p.Arg485Gln), indicating that these mutations cause a loss of function of the protein. Interpretation This study demonstrates that Depdc5 knockdown leads to early-onset phenotypic features related to motor and neuronal hyperactivity. Restoration of phenotypic features by WT but not epilepsy-associated Depdc5 mutants, as well as by mTORC1 inhibition confirm the role of Depdc5 in the mTORC1-dependent molecular cascades, defining this pathway as a potential therapeutic target for DEPDC5-inherited forms of focal epilepsy.
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Affiliation(s)
- Hortense de Calbiac
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France.,Institut Imagine UMR Inserm 1163 University Paris Descartes Hospital Necker-Enfants Malades 24 Boulevard du Montparnasse Paris 75015 France
| | - Adriana Dabacan
- Transylvanian Institute of Neuroscience (TINS) Str. Ploiesti 33 Cluj-Napoca 400157 Romania
| | - Elise Marsan
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Hervé Tostivint
- Evolution des Régulations Endocriniennes UMR 7221 CNRS and Muséum National d'Histoire Naturelle Paris France
| | - Gabrielle Devienne
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Saeko Ishida
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Eric Leguern
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Stéphanie Baulac
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France
| | - Raul C Muresan
- Transylvanian Institute of Neuroscience (TINS) Str. Ploiesti 33 Cluj-Napoca 400157 Romania
| | - Edor Kabashi
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France.,Institut Imagine UMR Inserm 1163 University Paris Descartes Hospital Necker-Enfants Malades 24 Boulevard du Montparnasse Paris 75015 France
| | - Sorana Ciura
- Sorbonne Universités Paris VI UMR CNRS 1127 UPMC INSERM U 1127 CNRS UMR 7225 Institut du Cerveau et de la Moelle épinière - ICM Paris France.,Institut Imagine UMR Inserm 1163 University Paris Descartes Hospital Necker-Enfants Malades 24 Boulevard du Montparnasse Paris 75015 France
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50
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Rácz A, Müller AM, Schwerdt J, Becker A, Vatter H, Elger CE. Age at epilepsy onset in patients with focal cortical dysplasias, gangliogliomas and dysembryoplastic neuroepithelial tumours. Seizure 2018; 58:82-89. [PMID: 29677585 DOI: 10.1016/j.seizure.2018.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 04/01/2018] [Accepted: 04/03/2018] [Indexed: 10/17/2022] Open
Abstract
PURPOSE The age at epilepsy onset in patients with inborn or very early acquired brain lesions depends on the epileptogenic potential of the lesion and the patients' individual "susceptibility" to epileptic seizures. To gain insight into these determinants, we analysed the case history of patients with focal cortical dysplasias (FCDs) and neuroglial tumours. METHODS In a systematic, retrospective analysis comprised of 233 patients who underwent surgery (116 with FCDs and 117 with neuroglial tumours), we evaluated the age at epilepsy onset according to histopathologic subgroups, lesion location and family history. RESULTS Epilepsy onset was significantly earlier in patients with FCD than for those with neuroglial tumours (FCDs: 8.06 ± 0.74 years, gangliogliomas: 15.86 ± 1.24 years, dysembryoplastic neuroepithelial tumours (DNTs): 19.18 ± 2.47 years; p < 0.00001). FCDs were most frequently located in the frontal, whereas neuroglial tumours most frequently in the temporal lobe. For FCD patients, the age at epilepsy onset was not dependent on lesion location, whereas DNTs in a temporal location were associated with a later epilepsy onset than gangliogliomas and extratemporal DNTs. A positive family history for epilepsy or epileptic seizures was found more frequently among patients with FCDs (FCDs: 20.4%, neuroglial tumours: 8.1%; p = 0.013). CONCLUSION We postulate that the age difference at epilepsy onset between patients with FCDs and neuroglial tumours can be attributed - at least partially - to unidentified genetic factors underlying the epileptogenic potential of the brain tissue. Additionally, the large variance in the age at epilepsy onset is possibly also genetically determined.
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Affiliation(s)
- Attila Rácz
- Department of Epileptology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53105 Bonn, Germany.
| | - Andreas-Markus Müller
- Department of Epileptology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
| | - Johannes Schwerdt
- Department of Neuropathology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
| | - Albert Becker
- Department of Neuropathology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
| | - Hartmut Vatter
- Department of Neurosurgery, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
| | - Christian E Elger
- Department of Epileptology, University of Bonn Medical Centre, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
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