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Donnellan EP, Kehoe C, Moran A, Ni Chollatain M, Hynes Y, Hennessy M, Reade E, Allen NM. The 2017 and 2022 ILAE epilepsy classification systems identify needs and opportunities in care: A paediatric hospital-based study. Epilepsy Behav 2024; 157:109804. [PMID: 38861909 DOI: 10.1016/j.yebeh.2024.109804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/08/2024] [Accepted: 04/17/2024] [Indexed: 06/13/2024]
Abstract
OBJECTIVES There is a paucity of studies reporting the epilepsy spectrum using the 2017 and 2022 ILAE classification systems in everyday clinical practice. To identify gaps and opportunities in care we evaluated a hospital-based cohort applying these epilepsy classification systems, including aetiology and co-morbidity, and the utility of molecular genetic diagnosis to identify available precision therapies. METHODS Cross sectional retrospective study of all children with epilepsy (≤16 years) attending University Hospital Galway (2017-2022). Data collection and analysis of each case was standardised to ensure a systematic approach and application of the recent ILAE categorisation and terminology (2017 and 2022). Ethics approval was obtained. RESULTS Among 356 children, epilepsy was classified as focal (46.1 %), generalised (38.8 %), combined (6.2 %), and unknown (9 %). Epilepsy syndrome was determined in 145/356 (40.7 %), comprising 24 different syndromes, most commonly SeLECTS (9 %), CAE (7 %), JAE (6.2 %) and IESS (5.9 %). New aetiology-specific syndromes were identified (e.g. CDKL5-DEE). Molecular diagnosis was confirmed in 19.9 % (n = 71) which encompassed monogenic (13.8 %) and chromosomopathy/CNV (6.2 %). There was an additional 35.7 % (n = 127) of patients who had a presumed genetic aetiology of epilepsy. Remaining aetiology included structural (18.8 %, n = 67), infectious (2 %, n = 7), metabolic (1.7 %, n = 6) and unknown (30.3 %, n = 108). Encephalopathy categorisation was determined in 182 patients (DE in 38.8 %; DEE in a further 11.8 %) associated with a range of co-morbidities categorised as global delay (29.2 %, n = 104), severe neurological impairment (16.3 %, n = 58), and ASD (14.6 %, n = 52). Molecular-based "precision therapy" was deemed available in 21/356 (5.9 %) patients, with "molecular precision" approach utilised in 13/356 (3.7 %), and some benefit noted in 6/356 (1.7 %) of overall cohort or 6/71 (8.5 %) of the molecular cohort. CONCLUSION Applying the latest ILAE epilepsy classification systems allow comparison across settings and identifies a major neuro-developmental co-morbidity rate and a large genetic aetiology. We identified very few meaningful molecular-based disease modifying "precision therapies". There is a monumental gap between aetiological identification, and impact of meaningful therapies, thus the new 2017/2022 classification clearly identifies the major challenges in the provision of routine epilepsy care.
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Affiliation(s)
| | - Caroline Kehoe
- Department of Paediatrics, Galway University Hospital, Ireland
| | - Ailbhe Moran
- Department of Paediatrics, Galway University Hospital, Ireland
| | | | - Yvonne Hynes
- Department of Paediatrics, Galway University Hospital, Ireland
| | | | - Elaine Reade
- Department of Paediatrics, Galway University Hospital, Ireland
| | - Nicholas M Allen
- Department of Paediatrics, Galway University Hospital, Ireland; Department of Paediatrics, School of Medicine, University of Galway, Ireland
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Elkhateeb N, Issa MY, Elbendary HM, Elnaggar W, Ramadan A, Rafat K, Kamel M, Abdel-Ghafar SF, Amer F, Hassaan HM, Trunzo R, Pereira C, Abdel-Hamid MS, D'Arco F, Bauer P, Bertoli-Avella AM, Girgis M, Gleeson JG, Zaki MS, Selim L. The clinical and genetic landscape of developmental and epileptic encephalopathies in Egyptian children. Clin Genet 2024; 105:510-522. [PMID: 38221827 DOI: 10.1111/cge.14481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/28/2023] [Accepted: 01/03/2024] [Indexed: 01/16/2024]
Abstract
Developmental and epileptic encephalopathies (DEEs) are a heterogeneous group of epilepsies characterized by early-onset, refractory seizures associated with developmental regression or impairment, with a heterogeneous genetic landscape including genes implicated in various pathways and mechanisms. We retrospectively studied the clinical and genetic data of patients with genetic DEE who presented at two tertiary centers in Egypt over a 10-year period. Exome sequencing was used for genetic testing. We report 74 patients from 63 unrelated Egyptian families, with a high rate of consanguinity (58%). The most common seizure type was generalized tonic-clonic (58%) and multiple seizure types were common (55%). The most common epilepsy syndrome was early infantile DEE (50%). All patients showed variable degrees of developmental impairment. Microcephaly, hypotonia, ophthalmological involvement and neuroimaging abnormalities were common. Eighteen novel variants were identified and the phenotypes of five DEE genes were expanded with novel phenotype-genotype associations. Obtaining a genetic diagnosis had implications on epilepsy management in 17 patients with variants in 12 genes. In this study, we expand the phenotype and genotype spectrum of DEE in a large single ethnic cohort of patients. Reaching a genetic diagnosis guided precision management of epilepsy in a significant proportion of patients.
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Affiliation(s)
- Nour Elkhateeb
- Department of Clinical Genetics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
- Department of Pediatrics, Pediatric Neurology and Metabolic Medicine Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Mahmoud Y Issa
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Hasnaa M Elbendary
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Walaa Elnaggar
- Department of Pediatrics, Pediatric Neurology and Metabolic Medicine Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Areef Ramadan
- Department of Pediatrics, Pediatric Neurology and Metabolic Medicine Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Karima Rafat
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Mona Kamel
- Department of Pediatrics, Pediatric Neurology and Metabolic Medicine Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Sherif F Abdel-Ghafar
- Department of Medical Molecular Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Fawzia Amer
- Department of Pediatrics, Pediatric Neurology and Metabolic Medicine Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Hebatallah M Hassaan
- Department of Pediatrics, Clinical Genetics Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
| | | | | | - Mohamed S Abdel-Hamid
- Department of Medical Molecular Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Felice D'Arco
- Radiology Department, Great Ormond Street Hospital for Children, London, UK
| | | | | | - Marian Girgis
- Department of Pediatrics, Pediatric Neurology and Metabolic Medicine Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
| | - Joseph G Gleeson
- Department of Neurosciences, University of California, San Diego, La Jolla, USA
- Rady Children's Hospital, Rady Children's Institute for Genomic Medicine, San Diego, La Jolla, USA
| | - Maha S Zaki
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Laila Selim
- Department of Pediatrics, Pediatric Neurology and Metabolic Medicine Unit, Kasr Al-Ainy School of Medicine, Cairo University, Cairo, Egypt
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Çapan ÖY, Yapıcı Z, Özbil M, Çağlayan HS. Exome data of developmental and epileptic encephalopathy patients reveals de novo and inherited pathologic variants in epilepsy-associated genes. Seizure 2024; 116:51-64. [PMID: 37353388 DOI: 10.1016/j.seizure.2023.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/04/2023] [Accepted: 06/10/2023] [Indexed: 06/25/2023] Open
Abstract
PURPOSE In Developmental and Epileptic Encephalopathies (DEEs), identifying the precise genetic factors guides the clinicians to apply the most appropriate treatment for the patient. Due to high locus heterogeneity, WES analysis is a promising approach for the genetic diagnosis of DEE. Therefore, the aim of the present study is to evaluate the utility of WES in the diagnosis and treatment of DEE patients. METHODS The exome data of 29 DEE patients were filtrated for destructive and missense mutations in 1896 epilepsy-related genes to detect the causative variants and examine the genotype-phenotype correlations. We performed Sanger sequencing with the available DNA samples to follow the co-segregation of the variants with the disease phenotype in the families. Also, the structural effects of p.Asn1053Ser, p.Pro120Ser and p.Glu1868Gly mutations on KCNMA1, NPC2, and SCN2A proteins, respectively, were evaluated by molecular dynamics (MD) and molecular docking simulations. RESULTS Out of 29, nine patients (31%) harbor pathological (P) or likely pathological (LP) mutations in SCN2A, KCNQ2, ATP1A2, KCNMA1, and MECP2 genes, and three patients have VUS variants (10%) in SCN1A and SCN2A genes. Sanger sequencing results indicated that three of the patients have de novo mutations while eight of them carry paternally and/or maternally inherited causative variants. MD and molecular docking simulations supported the destructive effects of the mutations on KCNMA1, NPC2, and SCN2A protein structures. CONCLUSION Herein we demonstrated the effectiveness of WES for DEE with high locus heterogeneity. Identification of the genetic etiology guided the clinicians to adjust the proper treatment for the patients.
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Affiliation(s)
- Özlem Yalçın Çapan
- Department of Medical Biology, Faculty of Medicine, Tekirdağ Namık Kemal University, Tekirdağ, Turkey; Department of Molecular Biology and Genetics, İstanbul Arel University, İstanbul, Turkey.
| | - Zuhal Yapıcı
- Division of Child Neurology, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Mehmet Özbil
- Institute of Biotechnology, Gebze Technical University, Kocaeli, Turkiye
| | - Hande S Çağlayan
- Department of Molecular Biology and Genetics, Boğaziçi University, İstanbul, Turkey (formerly)
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Baka RD, Kuleš J, Beletić A, Farkaš V, Rešetar Maslov D, Ljubić BB, Rubić I, Mrljak V, McLaughlin M, Eckersall D, Polizopoulou Z. Quantitative serum proteome analysis using tandem mass tags in dogs with epilepsy. J Proteomics 2024; 290:105034. [PMID: 37879566 DOI: 10.1016/j.jprot.2023.105034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/09/2023] [Accepted: 10/18/2023] [Indexed: 10/27/2023]
Abstract
This study included four groups of dogs (group A: healthy controls, group B: idiopathic epilepsy receiving antiepileptic medication (AEM), group C: idiopathic epilepsy without AEM, group D: structural epilepsy). Comparative quantitative proteomic analysis of serum samples among the groups was the main target of the study. Samples were analyzed by a quantitative Tandem-Mass-Tags approach on the Q-Exactive-Plus Hybrid Quadrupole-Orbitrap mass-spectrometer. Identification and relative quantification were performed in Proteome Discoverer. Data were analyzed using R. Gene ontology terms were analyzed based on Canis lupus familiaris database. Data are available via ProteomeXchange with identifier PXD041129. Eighty-one proteins with different relative adundance were identified in the four groups and 25 were master proteins (p < 0.05). Clusterin (CLU), and apolipoprotein A1 (APOA1) had higher abundance in the three groups of dogs (groups B, C, D) compared to controls. Amine oxidase (AOC3) was higher in abundance in group B compared to groups C and D, and lower in group A. Adiponectin (ADIPOQ) had higher abundance in groups C compared to group A. ADIPOQ and fibronectin (FN1) had higher abundance in group B compared to group C and D. Peroxidase activity assay was used to quantify HP abundance change, validating and correlating with proteomic analysis (r = 0.8796). SIGNIFICANCE: The proteomic analysis of serum samples from epileptic dogs indicated potential markers of epilepsy (CLU), proteins that may contribute to nerve tissue regeneration (APOA1), and contributing factors to epileptogenesis (AOC3). AEM could alter extracellular matrix proteins (FN1). Illness (epilepsy) severity could influence ADIPOQ abundance.
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Affiliation(s)
- Rania D Baka
- Diagnostic Laboratory, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | - Josipa Kuleš
- Department of Chemistry and Biochemistry, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Anđelo Beletić
- Laboratory of proteomics, Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Vladimir Farkaš
- Laboratory of proteomics, Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Dina Rešetar Maslov
- Laboratory of proteomics, Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Blanka Beer Ljubić
- Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Ivana Rubić
- Laboratory of proteomics, Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Vladimir Mrljak
- Laboratory of proteomics, Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia; Internal Diseases Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Marκ McLaughlin
- Institute of Biodiversity, Animal Health & Comparative Medicine and School of Veterinary Medicine, College of Medicine, Veterinary Medicine and Life Sciences,University of Glasgow, Glasgow G61 1QH, UK
| | - David Eckersall
- Institute of Biodiversity, Animal Health & Comparative Medicine and School of Veterinary Medicine, College of Medicine, Veterinary Medicine and Life Sciences,University of Glasgow, Glasgow G61 1QH, UK
| | - Zoe Polizopoulou
- Diagnostic Laboratory, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Lin SXN, Ahring PK, Keramidas A, Liao VWY, Møller RS, Chebib M, Absalom NL. Correlations of receptor desensitization of gain-of-function GABRB3 variants with clinical severity. Brain 2024; 147:224-239. [PMID: 37647766 PMCID: PMC10766243 DOI: 10.1093/brain/awad285] [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: 12/28/2022] [Revised: 08/01/2023] [Accepted: 08/17/2023] [Indexed: 09/01/2023] Open
Abstract
Genetic variants associated with developmental and epileptic encephalopathies have been identified in the GABRB3 gene that encodes the β3 subunit of GABAA receptors. Typically, variants alter receptor sensitivity to GABA resulting in either gain- or loss-of-function, which correlates with patient phenotypes. However, it is unclear how another important receptor property, desensitization, contributes to the greater clinical severity of gain-of-function variants. Desensitization properties of 20 gain-of-function GABRB3 variant receptors were evaluated using two-electrode voltage-clamp electrophysiology. The parameters measured included current decay rates and steady-state currents. Selected variants with increased or reduced desensitization were also evaluated using whole-cell electrophysiology in transfected mammalian cell lines. Of the 20 gain-of-function variants assessed, 13 were found to alter receptor desensitization properties. Seven variants reduced desensitization at equilibrium, which acts to worsen gain-of-function traits. Six variants accelerated current decay kinetics, which limits gain-of-function traits. All affected patients displayed severe clinical phenotypes with intellectual disability and difficult-to-treat epilepsy. Nevertheless, variants that reduced desensitization at equilibrium were associated with more severe clinical outcomes. This included younger age of first seizure onset (median 0.5 months), movement disorders (dystonia and dyskinesia), epilepsy of infancy with migrating focal seizures (EIMFS) and risk of early mortality. Variants that accelerated current decay kinetics were associated with slightly milder phenotypes with later seizure onset (median 4 months), unclassifiable developmental and epileptic encephalopathies or Lennox-Gastaut syndrome and no movement disorders. Our study reveals that gain-of-function GABRB3 variants can increase or decrease receptor desensitization properties and that there is a correlation with the degree of disease severity. Variants that reduced the desensitization at equilibrium were clustered in the transmembrane regions that constitute the channel pore and correlated with greater disease severity, while variants that accelerated current decay were clustered in the coupling loops responsible for receptor activation and correlated with lesser severity.
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Affiliation(s)
- Susan X N Lin
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Philip K Ahring
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Angelo Keramidas
- Institute for Molecular Bioscience, The University of Queensland, Saint Lucia, QLD 4072, Australia
| | - Vivian W Y Liao
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Member of ERN, EpiCare, Danish Epilepsy Centre, Dianalund DK-4293, Denmark
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense DK-5230, Denmark
| | - Mary Chebib
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Nathan L Absalom
- Brain and Mind Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Science, University of Western Sydney, Sydney, New South Wales, Australia
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Sampedro-Castañeda M, Baltussen LL, Lopes AT, Qiu Y, Sirvio L, Mihaylov SR, Claxton S, Richardson JC, Lignani G, Ultanir SK. Epilepsy-linked kinase CDKL5 phosphorylates voltage-gated calcium channel Cav2.3, altering inactivation kinetics and neuronal excitability. Nat Commun 2023; 14:7830. [PMID: 38081835 PMCID: PMC10713615 DOI: 10.1038/s41467-023-43475-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are a group of rare childhood disorders characterized by severe epilepsy and cognitive deficits. Numerous DEE genes have been discovered thanks to advances in genomic diagnosis, yet putative molecular links between these disorders are unknown. CDKL5 deficiency disorder (CDD, DEE2), one of the most common genetic epilepsies, is caused by loss-of-function mutations in the brain-enriched kinase CDKL5. To elucidate CDKL5 function, we looked for CDKL5 substrates using a SILAC-based phosphoproteomic screen. We identified the voltage-gated Ca2+ channel Cav2.3 (encoded by CACNA1E) as a physiological target of CDKL5 in mice and humans. Recombinant channel electrophysiology and interdisciplinary characterization of Cav2.3 phosphomutant mice revealed that loss of Cav2.3 phosphorylation leads to channel gain-of-function via slower inactivation and enhanced cholinergic stimulation, resulting in increased neuronal excitability. Our results thus show that CDD is partly a channelopathy. The properties of unphosphorylated Cav2.3 closely resemble those described for CACNA1E gain-of-function mutations causing DEE69, a disorder sharing clinical features with CDD. We show that these two single-gene diseases are mechanistically related and could be ameliorated with Cav2.3 inhibitors.
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Affiliation(s)
| | - Lucas L Baltussen
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Laboratory for the Research of Neurodegenerative Diseases (VIB-KU Leuven), Department of Neurosciences, ON5 Herestraat 49, 3000, Leuven, Belgium
| | - André T Lopes
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Yichen Qiu
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square House, London, WC1N 3BG, UK
| | - Liina Sirvio
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Simeon R Mihaylov
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Suzanne Claxton
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Jill C Richardson
- Neuroscience, MSD Research Laboratories, 120 Moorgate, London, EC2M 6UR, UK
| | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square House, London, WC1N 3BG, UK
| | - Sila K Ultanir
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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Geng G, Hu W, Meng Y, Zhang H, Zhang H, Chen C, Zhang Y, Gao Z, Liu Y, Shi J. Vagus nerve stimulation for treating developmental and epileptic encephalopathy in young children. Front Neurol 2023; 14:1191831. [PMID: 37928141 PMCID: PMC10624125 DOI: 10.3389/fneur.2023.1191831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 09/26/2023] [Indexed: 11/07/2023] Open
Abstract
Objective To investigate the clinical variables that might predict the outcome of developmental and epileptic encephalopathy (DEE) after vagus nerve stimulation (VNS) therapy and identify the risk factors for poor long-term outcome. Patients and methods We retrospectively studied 32 consecutive children with drug-resistant DEE who had undergone VNS surgery from April 2019 to July 2021, which were not suitable for corpus callosotomy. In spite of combining valproic acid, levetiracetam, lamotrigine, topiramate, etc. (standard anti-seizure medicine available in China) it has not been possible to effectively reduce seizures in the population we investigate (Cannabidiol and brivaracetam were not available in China). A responder was defined as a frequency reduction decrease > 50%. Seizure freedom was defined as freedom from seizures for at least 6 months. Sex, electroencephalograph (EEG) group, neurodevelopment, time lag, gene mutation, magnetic resonance imaging (MRI), and epilepsy syndrome were analyzed with Fisher's exact test, The age at onset and age at VNS therapy were analyzed with Kruskal-Wallis test, statistical significance was defined as p < 0.05. And used the effect size to correction. Results Among the 32 patients, the median age at VNS implantation was 4.7 years (range: 1-12 years). At the most recent follow-up, five children (15.6%) were seizure-free and 22 (68.8%) were responders. Univariate analysis demonstrated that the responders were significantly associated with mild development delay/intellectual disability (p = 0.044; phi coefficient = 0.357) and a multifocal EEG pattern (p = 0.022; phi coefficient = -0.405). Kaplan-Meier survival analyses demonstrated that a multifocal EEG pattern (p = 0.049) and DEE without epileptic spasm (ES) (p = 0.012) were statistically significant (p = 0.030). Multivariate analysis demonstrated that DEE with ES had significant predictive value for poor long-term outcome (p = 0.014, hazard ratio = 5.433, confidence interval = 1.402-21.058). Conclusions Our study suggested that VNS was a generally effective adjunct treatment for DEE. Although the predictive factors for VNS efficacy remain unclear, it should be emphasized that patients with ES are not suitable candidates for epilepsy surgery. Further investigations are needed to validate the present results.
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Affiliation(s)
- Guifu Geng
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
- Department of Functional Neurosurgery, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Wandong Hu
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Yao Meng
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
- Department of Functional Neurosurgery, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Huan Zhang
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Hongwei Zhang
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Chuanmei Chen
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Yanqing Zhang
- Pediatric Health Care Institute, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Zaifen Gao
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Yong Liu
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
| | - Jianguo Shi
- Department of Epilepsy Center, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
- Department of Functional Neurosurgery, Children's Hospital Affiliated to Shandong University, Jinan Children's Hospital, Jinan, Shandong, China
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Vidal E, Castro-Gutierrez E, Arisaca R, Paz-Valderrama A, Albiol-Pérez S. Serious Game for Fine Motor Control Rehabilitation for Children With Epileptic Encephalopathy: Development and Usability Study. JMIR Form Res 2023; 7:e50492. [PMID: 37788071 PMCID: PMC10582812 DOI: 10.2196/50492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 10/04/2023] Open
Abstract
BACKGROUND Epileptic encephalopathy (EE) is defined as the presence of frequent epileptiform activity that adversely impacts development, typically causing the slowing or regression of developmental skills, and is usually associated with frequent seizures. One of the main disturbances in EE is in the coordination of the upper extremities and hands. Traditional rehabilitation for this type of pathology focuses on the alleviation of gross or fine motor disability. In the last few years, the use of low-cost devices together with customized serious games has shown improvements in motor disorders and enrichments in activities of daily living. OBJECTIVE This study aims to explore the feasibility of a new serious game for improving fine motor control in children with EE. METHODS The participants were 4 children with EE (male: n=2, 50%; female: n=2, 50%) who were classified as belonging to level 1 in the Gross Motor Classification System. The children were tested over 10 sessions during the intervention period (before and after treatment). The clinical tests performed were the Bruininks-Oseretsky Test of Motor Proficiency, 2nd edition and Pittsburgh Rehabilitation Participation Scale. The subscales of the Bruininks-Oseretsky Test of Motor Proficiency, 2nd edition were fine motor precision, fine motor integration, manual dexterity, and upper-limb coordination. At the end of the first session, we used the User Satisfaction Evaluation Questionnaire to analyze user satisfaction. RESULTS The significance outcomes for a Student t test (1-tailed) were as follows: P=.009 for fine motor precision, P=.002 for fine motor integration, P=.56 for manual dexterity, and P=.99 for upper-limb coordination. The participation rate as measured using the Pittsburgh Rehabilitation Participation Scale was between good and very good, which means that, based on the therapist's evaluation, interest, independence, and motivation were achieved by each participant. The mean User Satisfaction Evaluation Questionnaire score was close to 30, which is the maximum value. CONCLUSIONS The results support the use of the proposed serious game as a complement in therapeutic sessions during the rehabilitation processes for children with EE. Significant improvements in fine motor control and activities of daily living revealed that the proposed serious game is beneficial for fine motor disorders of this pathology.
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Affiliation(s)
- Elizabeth Vidal
- Universidad Nacional de San Agustín de Arequipa, Arequipa, Peru
| | | | - Robert Arisaca
- Universidad Nacional de San Agustín de Arequipa, Arequipa, Peru
| | | | - Sergio Albiol-Pérez
- Aragón Health Research Institute (IIS Aragón), Universidad de Zaragoza, Teruel, Spain
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Sills GJ. Pharmacological diversity amongst approved and emerging antiseizure medications for the treatment of developmental and epileptic encephalopathies. Ther Adv Neurol Disord 2023; 16:17562864231191000. [PMID: 37655228 PMCID: PMC10467199 DOI: 10.1177/17562864231191000] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 07/13/2023] [Indexed: 09/02/2023] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are rare neurodevelopmental disorders characterised by early-onset and often intractable seizures and developmental delay/regression, and include Dravet syndrome and Lennox-Gastaut syndrome (LGS). Rufinamide, fenfluramine, stiripentol, cannabidiol and ganaxolone are antiseizure medications (ASMs) with diverse mechanisms of action that have been approved for treating specific DEEs. Rufinamide is thought to suppress neuronal hyperexcitability by preventing the functional recycling of voltage-gated sodium channels from the inactivated to resting state. It is licensed for adjunctive treatment of seizures associated with LGS. Fenfluramine increases extracellular serotonin levels and may reduce seizures via activation of specific serotonin receptors and positive modulation of the sigma-1 receptor. Fenfluramine is licensed for adjunctive treatment of seizures associated with Dravet syndrome and LGS. Stiripentol is a positive allosteric modulator of type-A gamma-aminobutyric acid (GABAA) receptors. As a broad-spectrum inhibitor of cytochrome P450 enzymes, its antiseizure effects may additionally arise through pharmacokinetic interactions with co-administered ASMs. Stiripentol is licensed for treating seizures associated with Dravet syndrome in patients taking clobazam and/or valproate. The mechanism(s) of action of cannabidiol remains largely unclear although multiple targets have been proposed, including transient receptor potential vanilloid 1, G protein-coupled receptor 55 and equilibrative nucleoside transporter 1. Cannabidiol is licensed as adjunctive treatment in conjunction with clobazam for seizures associated with Dravet syndrome and LGS, and as adjunctive treatment of seizures associated with tuberous sclerosis complex. Like stiripentol, ganaxolone is a positive allosteric modulator at GABAA receptors. It has recently been licensed in the USA for the treatment of seizures associated with cyclin-dependent kinase-like 5 deficiency disorder. Greater understanding of the causes of DEEs has driven research into the potential use of other novel and repurposed agents. Putative ASMs currently in clinical development for use in DEEs include soticlestat, carisbamate, verapamil, radiprodil, clemizole and lorcaserin.
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Affiliation(s)
- Graeme J. Sills
- School of Life Sciences, University of Glasgow, Room 341, Sir James Black Building, Glasgow G12 8QQ, UK
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10
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Chang YT, Hong SY, Lin WD, Lin CH, Lin SS, Tsai FJ, Chou IC. Genetic Testing in Children with Developmental and Epileptic Encephalopathies: A Review of Advances in Epilepsy Genomics. CHILDREN 2023; 10:children10030556. [PMID: 36980114 PMCID: PMC10047509 DOI: 10.3390/children10030556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/11/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023]
Abstract
Advances in disease-related gene discovery have led to tremendous innovations in the field of epilepsy genetics. Identification of genetic mutations that cause epileptic encephalopathies has opened new avenues for the development of targeted therapies. Clinical testing using extensive gene panels, exomes, and genomes is currently accessible and has resulted in higher rates of diagnosis and better comprehension of the disease mechanisms underlying the condition. Children with developmental disabilities have a higher risk of developing epilepsy. As our understanding of the mechanisms underlying encephalopathies and epilepsies improves, there may be greater potential to develop innovative therapies tailored to an individual’s genotype. This article provides an overview of the significant progress in epilepsy genomics in recent years, with a focus on developmental and epileptic encephalopathies in children. The aim of this review is to enhance comprehension of the clinical utilization of genetic testing in this particular patient population. The development of effective and precise therapeutic strategies for epileptic encephalopathies may be facilitated by a comprehensive understanding of their molecular pathogenesis.
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Affiliation(s)
- Yu-Tzu Chang
- School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung 40447, Taiwan; (Y.-T.C.)
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
| | - Syuan-Yu Hong
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Department of Medicine, School of Medicine, China Medical University, Taichung 40447, Taiwan
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40447, Taiwan
| | - Wei-De Lin
- School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung 40447, Taiwan; (Y.-T.C.)
- Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
| | - Chien-Heng Lin
- Division of Pediatric Pulmonology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Department of Biomedical Imaging and Radiological Science, College of Medicine, China Medial University, Taichung 40447, Taiwan
| | - Sheng-Shing Lin
- School of Post Baccalaureate Chinese Medicine, China Medical University, Taichung 40447, Taiwan; (Y.-T.C.)
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
| | - Fuu-Jen Tsai
- Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan
- Division of Genetics and Metabolism, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Department of Medical Genetics, China Medical University Hospital, Taichung 40447, Taiwan
- School of Chinese Medicine, China Medical University, Taichung 40447, Taiwan
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung 40447, Taiwan
| | - I-Ching Chou
- Division of Pediatric Neurology, China Medical University Children’s Hospital, Taichung 40447, Taiwan
- Graduate Institute of Integrated Medicine, China Medical University, Taichung 40447, Taiwan
- Correspondence: ; Tel.: +886-4-22052121
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11
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Silk M, de Sá A, Olshansky M, Ascher DB. Insights from Spatial Measures of Intolerance to Identifying Pathogenic Variants in Developmental and Epileptic Encephalopathies. Int J Mol Sci 2023; 24:ijms24065114. [PMID: 36982187 PMCID: PMC10049344 DOI: 10.3390/ijms24065114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/17/2023] [Accepted: 02/28/2023] [Indexed: 03/11/2023] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are a group of epilepsies with early onset and severe symptoms that sometimes lead to death. Although previous work successfully discovered several genes implicated in disease outcomes, it remains challenging to identify causative mutations within these genes from the background variation present in all individuals due to disease heterogeneity. Nevertheless, our ability to detect possible pathogenic variants has continued to improve as in silico predictors of deleteriousness have advanced. We investigate their use in prioritising likely pathogenic variants in epileptic encephalopathy patients’ whole exome sequences. We showed that the inclusion of structure-based predictors of intolerance improved upon previous attempts to demonstrate enrichment within epilepsy genes.
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Affiliation(s)
- Michael Silk
- Systems and Computational Biology, Bio21 Institute, University of Melbourne, Parkville, VIC 3052, Australia
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
| | - Alex de Sá
- Systems and Computational Biology, Bio21 Institute, University of Melbourne, Parkville, VIC 3052, Australia
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane City, QLD 4072, Australia
| | - Moshe Olshansky
- Systems and Computational Biology, Bio21 Institute, University of Melbourne, Parkville, VIC 3052, Australia
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
| | - David B. Ascher
- Systems and Computational Biology, Bio21 Institute, University of Melbourne, Parkville, VIC 3052, Australia
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane City, QLD 4072, Australia
- Correspondence: ; Tel.: +61-7-336-53891
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12
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Utility of genetic testing in children with developmental and epileptic encephalopathy (DEE) at a tertiary hospital in South Africa: A prospective study. Seizure 2022; 101:197-204. [DOI: 10.1016/j.seizure.2022.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/10/2022] [Accepted: 09/01/2022] [Indexed: 11/21/2022] Open
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13
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Yang S, Yang LM, Liao HM, Fang HJ, Ning ZS, Liao CS, Wu LW. Genetic analysis of developmental and epileptic encephalopathy caused by novel biallelic SZT2 gene mutations in three Chinese Han infants: a case series and literature review. Neurol Sci 2022; 43:5039-5048. [DOI: 10.1007/s10072-022-06038-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/21/2022] [Indexed: 11/28/2022]
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14
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Campbell C, Leu C, Feng YCA, Wolking S, Moreau C, Ellis C, Ganesan S, Martins H, Oliver K, Boothman I, Benson K, Molloy A, Brody L, Michaud JL, Hamdan FF, Minassian BA, Lerche H, Scheffer IE, Sisodiya S, Girard S, Cosette P, Delanty N, Lal D, Cavalleri GL. The role of common genetic variation in presumed monogenic epilepsies. EBioMedicine 2022; 81:104098. [PMID: 35679801 PMCID: PMC9188960 DOI: 10.1016/j.ebiom.2022.104098] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 05/11/2022] [Accepted: 05/20/2022] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The developmental and epileptic encephalopathies (DEEs) are the most severe group of epilepsies which co-present with developmental delay and intellectual disability (ID). DEEs usually occur in people without a family history of epilepsy and have emerged as primarily monogenic, with damaging rare mutations found in 50% of patients. Little is known about the genetic architecture of patients with DEEs in whom no pathogenic variant is identified. Polygenic risk scoring (PRS) is a method that measures a person's common genetic burden for a trait or condition. Here, we used PRS to test whether genetic burden for epilepsy is relevant in individuals with DEEs, and other forms of epilepsy with ID. METHODS Genetic data on 2,759 cases with DEEs, or epilepsy with ID presumed to have a monogenic basis, and 447,760 population-matched controls were analysed. We compared PRS for 'all epilepsy', 'focal epilepsy', and 'genetic generalised epilepsy' (GGE) between cases and controls. We performed pairwise comparisons between cases stratified for identifiable rare deleterious genetic variants and controls. FINDINGS Cases of presumed monogenic severe epilepsy had an increased PRS for 'all epilepsy' (p<0.0001), 'focal epilepsy' (p<0.0001), and 'GGE' (p=0.0002) relative to controls, which explain between 0.08% and 3.3% of phenotypic variance. PRS was increased in cases both with and without an identified deleterious variant of major effect, and there was no significant difference in PRS between the two groups. INTERPRETATION We provide evidence that common genetic variation contributes to the aetiology of DEEs and other forms of epilepsy with ID, even when there is a known pathogenic variant of major effect. These results provide insight into the genetic underpinnings of the severe epilepsies and warrant a shift in our understanding of the aetiology of the DEEs as complex, rather than monogenic, disorders. FUNDING Science foundation Ireland, Human Genome Research Institute; National Heart, Lung, and Blood Institute; German Research Foundation.
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Affiliation(s)
- Ciarán Campbell
- The SFI FutureNeuro Research Centre, RCSI Dublin, Republic of Ireland; The School of Pharmacy and Biomolecular Sciences, RCSI Dublin, Republic of Ireland
| | - Costin Leu
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America; UCL Queen Square Institute of Neurology, London WC1N 3BG and Chalfont Centre for Epilepsy, Bucks, United Kingdom; Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T, Cambridge, MA, United States of America
| | - Yen-Chen Anne Feng
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T, Cambridge, MA, United States of America; Division of Biostatistics, Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan
| | - Stefan Wolking
- Department of Neurology & Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Department of Epileptology and Neurology, University of Aachen, Aachen, Germany; Axe Neurosciences, Centre de recherche de l'Université de Montréal, Université de Montréal, Montréal, Canada
| | - Claudia Moreau
- Centre Intersectoriel en Santé Durable, Université du Québec à Chicoutimi, Saguenay, Canada
| | - Colin Ellis
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Shiva Ganesan
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Biomedical and Health Informatics (DBHi), Children's Hospital of Philadelphia, Philadelphia, PA 19146, USA; The Epilepsy NeuroGenetics Initiative (ENGIN), Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Helena Martins
- UCL Queen Square Institute of Neurology, London WC1N 3BG and Chalfont Centre for Epilepsy, Bucks, United Kingdom
| | - Karen Oliver
- Epilepsy Research Centre, Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia
| | - Isabelle Boothman
- The SFI FutureNeuro Research Centre, RCSI Dublin, Republic of Ireland; The School of Pharmacy and Biomolecular Sciences, RCSI Dublin, Republic of Ireland
| | - Katherine Benson
- The SFI FutureNeuro Research Centre, RCSI Dublin, Republic of Ireland; The School of Pharmacy and Biomolecular Sciences, RCSI Dublin, Republic of Ireland
| | - Anne Molloy
- Department of Medical Gerontology, School of Medicine, Trinity College Dublin, Dublin 2, Republic of Ireland
| | - Lawrence Brody
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Fadi F Hamdan
- CHU Sainte-Justine Research Center, Montreal, Quebec, Canada
| | - Berge A Minassian
- Department of Pediatrics, Hospital for Sick Children and University of Toronto, Toronto, Canada
| | - Holger Lerche
- Department of Neurology & Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Ingrid E Scheffer
- University of Melbourne, Austin and Royal Children's Hospitals, Melbourne, Australia; Florey Institute and Murdoch Children's Research Institute, Melbourne, Australia
| | - Sanjay Sisodiya
- UCL Queen Square Institute of Neurology, London WC1N 3BG and Chalfont Centre for Epilepsy, Bucks, United Kingdom
| | - Simon Girard
- Centre Intersectoriel en Santé Durable, Université du Québec à Chicoutimi, Saguenay, Canada
| | - Patrick Cosette
- Department of Medicine, Neurology Division, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada
| | - Norman Delanty
- The School of Pharmacy and Biomolecular Sciences, RCSI Dublin, Republic of Ireland; Department of Neurology, Beaumont Hospital, Dublin, Republic of Ireland
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America; Stanley Center for Psychiatric Research, Broad Institute of Harvard and M.I.T, Cambridge, MA, United States of America; Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA; Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Gianpiero L Cavalleri
- The SFI FutureNeuro Research Centre, RCSI Dublin, Republic of Ireland; The School of Pharmacy and Biomolecular Sciences, RCSI Dublin, Republic of Ireland.
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15
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Löscher W. Dogs as a Natural Animal Model of Epilepsy. Front Vet Sci 2022; 9:928009. [PMID: 35812852 PMCID: PMC9257283 DOI: 10.3389/fvets.2022.928009] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 05/18/2022] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a common neurological disease in both humans and domestic dogs, making dogs an ideal translational model of epilepsy. In both species, epilepsy is a complex brain disease characterized by an enduring predisposition to generate spontaneous recurrent epileptic seizures. Furthermore, as in humans, status epilepticus is one of the more common neurological emergencies in dogs with epilepsy. In both species, epilepsy is not a single disease but a group of disorders characterized by a broad array of clinical signs, age of onset, and underlying causes. Brain imaging suggests that the limbic system, including the hippocampus and cingulate gyrus, is often affected in canine epilepsy, which could explain the high incidence of comorbid behavioral problems such as anxiety and cognitive alterations. Resistance to antiseizure medications is a significant problem in both canine and human epilepsy, so dogs can be used to study mechanisms of drug resistance and develop novel therapeutic strategies to benefit both species. Importantly, dogs are large enough to accommodate intracranial EEG and responsive neurostimulation devices designed for humans. Studies in epileptic dogs with such devices have reported ictal and interictal events that are remarkably similar to those occurring in human epilepsy. Continuous (24/7) EEG recordings in a select group of epileptic dogs for >1 year have provided a rich dataset of unprecedented length for studying seizure periodicities and developing new methods for seizure forecasting. The data presented in this review substantiate that canine epilepsy is an excellent translational model for several facets of epilepsy research. Furthermore, several techniques of inducing seizures in laboratory dogs are discussed as related to therapeutic advances. Importantly, the development of vagus nerve stimulation as a novel therapy for drug-resistant epilepsy in people was based on a series of studies in dogs with induced seizures. Dogs with naturally occurring or induced seizures provide excellent large-animal models to bridge the translational gap between rodents and humans in the development of novel therapies. Furthermore, because the dog is not only a preclinical species for human medicine but also a potential patient and pet, research on this species serves both veterinary and human medicine.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Center for Systems Neuroscience, Hannover, Germany
- *Correspondence: Wolfgang Löscher
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16
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Lin JJ, Meletti S, Vaudano AE, Lin KL. Developmental and epileptic encephalopathies: Is prognosis related to different epileptic network dysfunctions? Epilepsy Behav 2022; 131:107654. [PMID: 33349540 DOI: 10.1016/j.yebeh.2020.107654] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 11/19/2022]
Abstract
Developmental and epileptic encephalopathies are a group of rare, severe epilepsies, which are characterized by refractory seizures starting in infancy or childhood and developmental delay or regression. Developmental changes might be independent of epilepsy. However, interictal epileptic activity and seizures can further deteriorate cognition and behavior. Recently, the concept of developmental and epileptic encephalopathies has moved from the lesions associated with epileptic encephalopathies toward the epileptic network dysfunctions on the functioning of the brain. Early recognition and differentiation of patients with developmental and epileptic encephalopathies is important, as precision therapies need to be holistic to address the often devastating symptoms. In this review, we discuss the evolution of the concept of developmental and epileptic encephalopathies in recent years, as well as the current understanding of the genetic basis of developmental and epileptic encephalopathies. Finally, we will discuss the role of epileptic network dysfunctions on prognosis for these severe conditions.
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Affiliation(s)
- Jainn-Jim Lin
- Division of Pediatric Critical Care and Pediatric Neurocritical Care Center, Chang Gung Children's Hospital and Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Graduate Institute of Clinical Medical Sciences, Chang Gung University, College of Medicine, Taoyuan, Taiwan; Division of Pediatric Neurology, Chang Gung Children's Hospital and Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Department of Respiratory Therapy, Chang Gung Children's Hospital and Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Study Group for Intensive and Integrated Care of Pediatric Central Nervous System (iCNS Group), Chang Gung Children's Hospital, Taoyuan, Taiwan
| | - Stefano Meletti
- Division of Neurology, University Hospital of Modena, Modena, Italy; Department of Biomedical, Metabolic and Neural Science, University of Modena and Reggio Emilia, Modena, Italy
| | - Anna Elisabetta Vaudano
- Division of Neurology, University Hospital of Modena, Modena, Italy; Department of Biomedical, Metabolic and Neural Science, University of Modena and Reggio Emilia, Modena, Italy
| | - Kuang-Lin Lin
- Division of Pediatric Neurology, Chang Gung Children's Hospital and Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Study Group for Intensive and Integrated Care of Pediatric Central Nervous System (iCNS Group), Chang Gung Children's Hospital, Taoyuan, Taiwan.
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17
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Al Masseri Z, AlSayed M. Gonadal mosaicism in GNAO1 causing neurodevelopmental disorder with involuntary movements; two additional variants. Mol Genet Metab Rep 2022; 31:100864. [PMID: 35782616 PMCID: PMC9248221 DOI: 10.1016/j.ymgmr.2022.100864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/19/2022] [Accepted: 03/20/2022] [Indexed: 11/25/2022] Open
Abstract
Background GNAO1 encodes an alpha subunit of the heterotrimeric guanine nucleotide-binding proteins (G proteins). Mutations in GNAO1 result in two clinical phenotypes: Early infantile epileptic encephalopathy 17 (EEIE17-OMIM #615473) and Neurodevelopmental disorder with involuntary movements (NEDIM-OMIM #617493). Both are inherited as autosomal dominant disorders and originate mainly as de novo. Only a few are reported as gonadal mosaicism. Materials and methods We recruited and retrospectively reviewed five patients from two families seen at King Faisal Specialist Hospital and Research Centre in Riyadh (KFSHRC). Results All patients presented with severe neurodevelopmental disorder, followed by progressive dystonia and hyperkinetic movements. In addition, none of the patients had seizures which was consistent with NEDIM phenotype. The specific diagnosis was not clinically entertained and was only found on whole exome sequencing (WES), which identified two variants (c.724-8G > A & c.709G > A). Both variants were previously reported as pathogenic de novo in patients with NEDIM, and one was reported as parental gonadal mosaicism. Conclusion We report these variants as additional variants in GNAO1 gene that may be inherited as parental gonadal mosaicism. Both variants resulted in NEDIM with no observed clinical differences in the severity than the reported cases. This noticeable reported association between GNAO1 gene associated disorders and gonadal mosaicism should be considered in reproductive genetic counselling of affected families. Furthermore, in view of these reports, more studies with prospective data collection to explore the association between GNAO1 and gonadal mosaicism and the underlying mechanisms will be necessary.
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Demarest S, Calhoun J, Eschbach K, Yu HC, Mirsky D, Angione K, Shaikh TH, Carvill GL, Benke TA, Gunti J, Vanderveen G. Whole-exome sequencing and adrenocorticotropic hormone therapy in individuals with infantile spasms. Dev Med Child Neurol 2022; 64:633-640. [PMID: 35830182 DOI: 10.1111/dmcn.15109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 10/22/2021] [Accepted: 10/25/2021] [Indexed: 12/20/2022]
Abstract
AIM To identify additional genes associated with infantile spasms using a cohort with defined infantile spasms. METHOD Whole-exome sequencing (WES) was performed on 21 consented individuals with infantile spasms and their unaffected parents (a trio-based study). Clinical history and imaging were reviewed. Potentially deleterious exonic variants were identified and segregated. To refine potential candidates, variants were further prioritized on the basis of evidence for relevance to disease phenotype or known associations with infantile spasms, epilepsy, or neurological disease. RESULTS Likely pathogenic de novo variants were identified in NR2F1, GNB1, NEUROD2, GABRA2, and NDUFAF5. Suggestive dominant and recessive candidate variants were identified in PEMT, DYNC1I1, ASXL1, RALGAPB, and STRADA; further confirmation is required to support their relevance to disease etiology. INTERPRETATION This study supports the utility of WES in uncovering the genetic etiology in undiagnosed individuals with infantile spasms with an overall yield of five out of 21. High-priority candidates were identified in an additional five individuals. WES provides additional support for previously described disease-associated genes and expands their already broad mutational and phenotypic spectrum.
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Affiliation(s)
- Scott Demarest
- Children's Hospital Colorado, Aurora, CO, USA.,Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Jeff Calhoun
- Ken and Ruth Davee Department of Neurology, Northwestern University, School of Medicine, Chicago, IL, USA
| | - Krista Eschbach
- Children's Hospital Colorado, Aurora, CO, USA.,Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Hung-Chun Yu
- Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA
| | - David Mirsky
- Children's Hospital Colorado, Aurora, CO, USA.,Department of Radiology, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Katie Angione
- Children's Hospital Colorado, Aurora, CO, USA.,Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Tamim H Shaikh
- Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA
| | - Gemma L Carvill
- Ken and Ruth Davee Department of Neurology, Northwestern University, School of Medicine, Chicago, IL, USA.,Department of Pharmacology, Northwestern University, School of Medicine, Chicago, IL, USA.,Department of Pediatrics, Northwestern University, School of Medicine, Chicago, IL, USA
| | - Tim A Benke
- Children's Hospital Colorado, Aurora, CO, USA.,Department of Pediatrics, University of Colorado, School of Medicine, Aurora, CO, USA.,Department of Pharmacology, University of Colorado, School of Medicine, Aurora, CO, USA.,Department of Neurology, University of Colorado, School of Medicine, Aurora, CO, USA.,Department of Otolaryngology, University of Colorado, School of Medicine, Aurora, CO, USA
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19
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Hieu NLT, Thu NTM, Ngan LTA, Van LTK, Huy DP, Linh PTT, Mai NTQ, Hien HTD, Hang DTT. Genetic analysis using targeted exome sequencing of 53 Vietnamese children with developmental and epileptic encephalopathies. Am J Med Genet A 2022; 188:2048-2060. [PMID: 35365919 DOI: 10.1002/ajmg.a.62741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 01/14/2022] [Accepted: 03/13/2022] [Indexed: 11/07/2022]
Abstract
Developmental and epileptic encephalopathies (DEE) refers to a group of rare and severe neurodevelopmental disorders where genetic etiologies can play a major role. This study aimed to elucidate the genetic etiologies of a cohort of 53 Vietnamese patients with DEE. All patients were classified into known electroclinical syndromes where possible. Exome sequencing (ES) followed by a targeted analysis on 294 DEE-related genes was then performed. Patients with identified causative variants were followed for 6 months to determine the impact of genetic testing on their treatment. The diagnostic yield was 38.0% (20/53), which was significantly higher in the earlier onset group (<12 months) than in the later onset group (≥12 months). The 19 identified variants belonged to 11 genes with various cellular functions. Genes encoding ion channels especially sodium voltage-gated channel were the most frequently involved. Most variants were missense variants and located in key protein functional domains. Four variants were novel and four had been reported previously but in different phenotypes. Within 6 months of further follow-up, treatment changes were applied for six patients based on the identified disease-causing variants, with five patients showing a positive impact. This is the first study in Vietnam to analyze the genetics of DEE. This study confirms the strong involvement of genetic etiologies in DEE, especially early onset DEE. The study also contributes to clarify the genotype-phenotype correlations of DEE and highlights the efficacy of targeted ES in the diagnosis and treatment of DEE.
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Affiliation(s)
- Nguyen Le Trung Hieu
- Neurology Department, Children Hospital 2, Ho Chi Minh City, Vietnam.,University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam
| | | | - Le Tran Anh Ngan
- Neurology Department, Children Hospital 2, Ho Chi Minh City, Vietnam
| | - Le Thi Khanh Van
- Neurology Department, Children Hospital 2, Ho Chi Minh City, Vietnam
| | - Do Phuoc Huy
- Medical Genetics Institute, Ho Chi Minh City, Vietnam
| | - Pham Thi Truc Linh
- Functional Genomic Unit, DNA Medical Technology Company, Ho Chi Minh City, Vietnam
| | - Nguyen Thi Quynh Mai
- Research Center for Genetics and Reproductive Health, School of Medicine, Vietnam National University, Ho Chi Minh City, Vietnam
| | - Huynh Thi Dieu Hien
- Research Center for Genetics and Reproductive Health, School of Medicine, Vietnam National University, Ho Chi Minh City, Vietnam
| | - Do Thi Thu Hang
- Research Center for Genetics and Reproductive Health, School of Medicine, Vietnam National University, Ho Chi Minh City, Vietnam
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20
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The Genetic Diagnosis of Ultrarare DEEs: An Ongoing Challenge. Genes (Basel) 2022; 13:genes13030500. [PMID: 35328054 PMCID: PMC8953579 DOI: 10.3390/genes13030500] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 02/06/2023] Open
Abstract
Epileptic encephalopathies (EEs) and developmental and epileptic encephalopathies (DEEs) are a group of severe early-onset neurodevelopmental disorders (NDDs). In recent years, next-generation equencing (NGS) technologies enabled the discovery of numerous genes involved in these conditions. However, more than 50% of patients remained undiagnosed. A major obstacle lies in the high degree of genetic heterogeneity and the wide phenotypic variability that has characterized these disorders. Interpreting a large amount of NGS data is also a crucial challenge. This study describes a dynamic diagnostic procedure used to investigate 17 patients with DEE or EE with previous negative or inconclusive genetic testing by whole-exome sequencing (WES), leading to a definite diagnosis in about 59% of participants. Biallelic mutations caused most of the diagnosed cases (50%), and a pathogenic somatic mutation resulted in 10% of the subjects. The high diagnostic yield reached highlights the relevance of the scientific approach, the importance of the reverse phenotyping strategy, and the involvement of a dedicated multidisciplinary team. The study emphasizes the role of recessive and somatic variants, new genetic mechanisms, and the complexity of genotype–phenotype associations. In older patients, WES results could end invasive diagnostic procedures and allow a more accurate transition. Finally, an early pursued diagnosis is essential for comprehensive care of patients, precision approach, knowledge of prognosis, patient and family planning, and quality of life.
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21
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Madaan P, Kaur A, Saini L, Paria P, Vyas S, Sharma AR, Sahu JK. PPP2R5D-Related Neurodevelopmental Disorder or Developmental and Epileptic Encephalopathy?: A Novel Phenotypic Description and Review of Published Cases. Neuropediatrics 2022; 53:20-25. [PMID: 34448180 DOI: 10.1055/s-0041-1733984] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Protein phosphatase 2 regulatory subunit B' delta (PPP2R5D)-related neurodevelopmental disorder is caused by pathogenic variations in the PPP2R5D gene, product of which is involved in dephosphorylation. This is a rare disorder with description limited to case reports. Its phenotypic spectrum has expanded over the last decade. METHODS We report a child with a developmental and epileptic encephalopathy phenotype with a pathogenic PPP2R5D variant. This phenotype has not been previously reported. We also reviewed the previously published reports of patients with this disorder. RESULTS Including the index child, 28 cases (15 girls) were identified from nine relevant research items for analysis. All patients had developmental delay. History of seizures was observed in seven patients while macrocephaly was seen in nearly 80% of patients. Nonneurological manifestations were observed in 13 patients with the most common one being ophthalmological manifestations. The most common genetic variation was c.G592A (p.E198K). The common phenotypic associations of this variation were developmental delay, macrocephaly (11/15), and epilepsy (6/15). CONCLUSION PPP2R5D gene variations should be suspected in children with developmental delay, autistic features, macrocephaly with or without epilepsy in the absence of any clear etiology. Dysmorphic features might provide a diagnostic clue. DEE phenotype may also be the presenting feature and might be an underreported entity.
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Affiliation(s)
- Priyanka Madaan
- Pediatric Neurology Unit, Department of Pediatrics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Amrit Kaur
- Department of Pediatrics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Lokesh Saini
- Pediatric Neurology Unit, Department of Pediatrics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India.,Department of Pediatrics, All India Institute of Medical Sciences, Jodhpur, India
| | - Pradip Paria
- Pediatric Neurology Unit, Department of Pediatrics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Sameer Vyas
- Department of Radiodiagnosis and Imaging (Section of Neuroimaging and Interventional Radiology), Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Amit R Sharma
- Department of Neurology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Jitendra K Sahu
- Pediatric Neurology Unit, Department of Pediatrics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
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22
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Whitlock JH, Soelter TM, Williams AS, Hardigan AA, Lasseigne BN. Liquid biopsies in epilepsy: biomarkers for etiology, diagnosis, prognosis, and therapeutics. Hum Cell 2022; 35:15-22. [PMID: 34694568 PMCID: PMC8732818 DOI: 10.1007/s13577-021-00624-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 09/29/2021] [Indexed: 01/19/2023]
Abstract
Epilepsy is one of the most common diseases of the central nervous system, impacting nearly 50 million people around the world. Heterogeneous in nature, epilepsy presents in children and adults alike. Currently, surgery is one treatment approach that can completely cure epilepsy. However, not all individuals are eligible for surgical procedures or have successful outcomes. In addition to surgical approaches, antiepileptic drugs (AEDs) have also allowed individuals with epilepsy to achieve freedom from seizures. Others have found treatment through nonpharmacologic approaches such as vagus nerve stimulation, or responsive neurostimulation. Difficulty in accessing samples of human brain tissue along with advances in sequencing technology have driven researchers to investigate sampling liquid biopsies in blood, serum, plasma, and cerebrospinal fluid within the context of epilepsy. Liquid biopsies provide minimal or non-invasive sample collection approaches and can be assayed relatively easily across multiple time points, unlike tissue-based sampling. Various efforts have investigated circulating nucleic acids from these samples including microRNAs, cell-free DNA, transfer RNAs, and long non-coding RNAs. Here, we review nucleic acid-based liquid biopsies in epilepsy to improve understanding of etiology, diagnosis, prediction, and therapeutic monitoring.
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Affiliation(s)
- Jordan H Whitlock
- Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tabea M Soelter
- Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Avery S Williams
- Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Andrew A Hardigan
- Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA
| | - Brittany N Lasseigne
- Cell, Developmental and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA.
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23
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Martinez-Esteve Melnikova A, Pijuan J, Aparicio J, Ramírez A, Altisent-Huguet A, Vilanova-Adell A, Arzimanoglou A, Armstrong J, Palau F, Hoenicka J, San Antonio-Arce V. The p.Glu787Lys variant in the GRIA3 gene causes developmental and epileptic encephalopathy mimicking structural epilepsy in a female patient. Eur J Med Genet 2022; 65:104442. [DOI: 10.1016/j.ejmg.2022.104442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/28/2021] [Accepted: 01/22/2022] [Indexed: 11/03/2022]
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24
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Stenshorne I, Syvertsen M, Ramm-Pettersen A, Henning S, Weatherup E, Bjørnstad A, Brüggemann N, Spetalen T, Selmer KK, Koht J. Monogenic developmental and epileptic encephalopathies of infancy and childhood, a population cohort from Norway. Front Pediatr 2022; 10:965282. [PMID: 35979408 PMCID: PMC9376386 DOI: 10.3389/fped.2022.965282] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/07/2022] [Indexed: 12/01/2022] Open
Abstract
INTRODUCTION Developmental and epileptic encephalopathies (DEE) is a group of epilepsies where the epileptic activity, seizures and the underlying neurobiology contributes to cognitive and behavioral impairments. Uncovering the causes of DEE is important in order to develop guidelines for treatment and follow-up. The aim of the present study was to describe the clinical picture and to identify genetic causes in a patient cohort with DEE without known etiology, from a Norwegian regional hospital. METHODS Systematic searches of medical records were performed at Drammen Hospital, Vestre Viken Health Trust, to identify patients with epilepsy in the period 1999-2018. Medical records were reviewed to identify patients with DEE of unknown cause. In 2018, patients were also recruited consecutively from treating physicians. All patients underwent thorough clinical evaluation and updated genetic diagnostic analyses. RESULTS Fifty-five of 2,225 patients with epilepsy had DEE of unknown etiology. Disease-causing genetic variants were found in 15/33 (45%) included patients. Three had potentially treatable metabolic disorders (SLC2A1, COQ4 and SLC6A8). Developmental comorbidity was higher in the group with a genetic diagnosis, compared to those who remained undiagnosed. Five novel variants in known genes were found, and the patient phenotypes are described. CONCLUSION The results from this study illustrate the importance of performing updated genetic investigations and/or analyses in patients with DEE of unknown etiology. A genetic cause was identified in 45% of the patients, and three of these patients had potentially treatable conditions where available targeted therapy may improve patient outcome.
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Affiliation(s)
- Ida Stenshorne
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Marte Syvertsen
- Department of Neurology, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Anette Ramm-Pettersen
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Clinical Neurosciences for Children, Oslo University Hospital, Oslo, Norway
| | - Susanne Henning
- Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Elisabeth Weatherup
- Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Alf Bjørnstad
- Department of Children and Adolescents, Stavanger University Hospital, Stavanger Health Trust, Stavanger, Norway
| | - Natalia Brüggemann
- Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Torstein Spetalen
- Department of Neurology, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Kaja K Selmer
- National Center for Epilepsy, Oslo University Hospital, Oslo, Norway.,Division of Clinical Neuroscience, Department of Research and Innovation, Oslo University Hospital, Oslo, Norway
| | - Jeanette Koht
- Department of Neurology, Oslo University Hospital, Oslo, Norway
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25
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Benke TA, Park K, Krey I, Camp CR, Song R, Ramsey AJ, Yuan H, Traynelis SF, Lemke J. Clinical and therapeutic significance of genetic variation in the GRIN gene family encoding NMDARs. Neuropharmacology 2021; 199:108805. [PMID: 34560056 PMCID: PMC8525401 DOI: 10.1016/j.neuropharm.2021.108805] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 02/03/2023]
Abstract
Considerable genetic variation of N-methyl-d-aspartate receptors (NMDARs) has recently become apparent, with many hundreds of de novo variants identified through widely available clinical genetic testing. Individuals with GRIN variants present with neurological conditions such as epilepsy, autism, intellectual disability (ID), movement disorders, schizophrenia and behavioral disorders. Determination of the functional consequence of genetic variation for NMDARs should lead to precision therapeutics. Furthermore, genetic animal models harboring human variants have the potential to reveal mechanisms that are shared among different neurological conditions, providing strategies that may allow treatment of individuals who are refractory to therapy. Preclinical studies in animal models and small open label trials in humans support this idea. However, additional functional data for variants and animal models corresponding to multiple individuals with the same genotype are needed to validate this approach and to lead to thoughtfully designed, randomized, placebo-controlled clinical trials, which could provide data in order to determine safety and efficacy of potential precision therapeutics.
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Affiliation(s)
- Tim A Benke
- Departments of Pediatrics, Pharmacology, Neurology, and Otolaryngology, University of Colorado, School of Medicine and Children's Hospital Colorado, United States.
| | - Kristen Park
- Departments of Pediatrics and Neurology, University of Colorado School of Medicine and Children's Hospital Colorado, United States
| | - Ilona Krey
- Institute of Human Genetics, Leipzig Medical Center, Leipzig, Germany
| | - Chad R Camp
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Rui Song
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Amy J Ramsey
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Stephen F Traynelis
- Department of Pharmacology and Chemical Biology and the Center for Functional Evaluation of Rare Variants, Emory University School of Medicine, Atlanta, GA, United States
| | - Johannes Lemke
- Institute of Human Genetics, Leipzig Medical Center, Leipzig, Germany
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26
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Distinct gene-set burden patterns underlie common generalized and focal epilepsies. EBioMedicine 2021; 72:103588. [PMID: 34571366 PMCID: PMC8479647 DOI: 10.1016/j.ebiom.2021.103588] [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: 05/24/2021] [Revised: 09/04/2021] [Accepted: 09/06/2021] [Indexed: 01/02/2023] Open
Abstract
Background Analyses of few gene-sets in epilepsy showed a potential to unravel key disease associations. We set out to investigate the burden of ultra-rare variants (URVs) in a comprehensive range of biologically informed gene-sets presumed to be implicated in epileptogenesis. Methods The burden of 12 URV types in 92 gene-sets was compared between cases and controls using whole exome sequencing data from individuals of European descent with developmental and epileptic encephalopathies (DEE, n = 1,003), genetic generalized epilepsy (GGE, n = 3,064), or non-acquired focal epilepsy (NAFE, n = 3,522), collected by the Epi25 Collaborative, compared to 3,962 ancestry-matched controls. Findings Missense URVs in highly constrained regions were enriched in neuron-specific and developmental genes, whereas genes not expressed in brain were not affected. GGE featured a higher burden in gene-sets derived from inhibitory vs. excitatory neurons or associated receptors, whereas the opposite was found for NAFE, and DEE featured a burden in both. Top-ranked susceptibility genes from recent genome-wide association studies (GWAS) and gene-sets derived from generalized vs. focal epilepsies revealed specific enrichment patterns of URVs in GGE vs. NAFE. Interpretation Missense URVs affecting highly constrained sites differentially impact genes expressed in inhibitory vs. excitatory pathways in generalized vs. focal epilepsies. The excess of URVs in top-ranked GWAS risk-genes suggests a convergence of rare deleterious and common risk-variants in the pathogenesis of generalized and focal epilepsies. Funding DFG Research Unit FOR-2715 (Germany), FNR (Luxembourg), NHGRI (US), NHLBI (US), DAAD (Germany).
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27
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Stringer RN, Jurkovicova-Tarabova B, Souza IA, Ibrahim J, Vacik T, Fathalla WM, Hertecant J, Zamponi GW, Lacinova L, Weiss N. De novo SCN8A and inherited rare CACNA1H variants associated with severe developmental and epileptic encephalopathy. Mol Brain 2021; 14:126. [PMID: 34399820 PMCID: PMC8365958 DOI: 10.1186/s13041-021-00838-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 08/01/2021] [Indexed: 02/08/2023] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are a group of severe epilepsies that are characterized by seizures and developmental delay. DEEs are primarily attributed to genetic causes and an increasing number of cases have been correlated with variants in ion channel genes. In this study, we report a child with an early severe DEE. Whole exome sequencing showed a de novo heterozygous variant (c.4873–4881 duplication) in the SCN8A gene and an inherited heterozygous variant (c.952G > A) in the CACNA1H gene encoding for Nav1.6 voltage-gated sodium and Cav3.2 voltage-gated calcium channels, respectively. In vitro functional analysis of human Nav1.6 and Cav3.2 channel variants revealed mild but significant alterations of their gating properties that were in general consistent with a gain- and loss-of-channel function, respectively. Although additional studies will be required to confirm the actual pathogenic involvement of SCN8A and CACNA1H, these findings add to the notion that rare ion channel variants may contribute to the etiology of DEEs.
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Affiliation(s)
- Robin N Stringer
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.,Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Bohumila Jurkovicova-Tarabova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Ivana A Souza
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Judy Ibrahim
- Department of Pediatrics, Tawam Hospital, Al-Ain, United Arab Emirates
| | - Tomas Vacik
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | | | - Jozef Hertecant
- Department of Pediatrics, Tawam Hospital, Al-Ain, United Arab Emirates.,Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al-Ain, United Arab Emirates
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Lubica Lacinova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Norbert Weiss
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic. .,Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic. .,Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia. .,Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic.
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28
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Delineating the molecular and phenotypic spectrum of the SETD1B-related syndrome. Genet Med 2021; 23:2122-2137. [PMID: 34345025 PMCID: PMC8553606 DOI: 10.1038/s41436-021-01246-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose Pathogenic variants in SETD1B have been associated with a syndromic neurodevelopmental disorder including intellectual disability, language delay, and seizures. To date, clinical features have been described for 11 patients with (likely) pathogenic SETD1B sequence variants. This study aims to further delineate the spectrum of the SETD1B-related syndrome based on characterizing an expanded patient cohort. Methods We perform an in-depth clinical characterization of a cohort of 36 unpublished individuals with SETD1B sequence variants, describing their molecular and phenotypic spectrum. Selected variants were functionally tested using in vitro and genome-wide methylation assays. Results Our data present evidence for a loss-of-function mechanism of SETD1B variants, resulting in a core clinical phenotype of global developmental delay, language delay including regression, intellectual disability, autism and other behavioral issues, and variable epilepsy phenotypes. Developmental delay appeared to precede seizure onset, suggesting SETD1B dysfunction impacts physiological neurodevelopment even in the absence of epileptic activity. Males are significantly overrepresented and more severely affected, and we speculate that sex-linked traits could affect susceptibility to penetrance and the clinical spectrum of SETD1B variants. Conclusion Insights from this extensive cohort will facilitate the counseling regarding the molecular and phenotypic landscape of newly diagnosed patients with the SETD1B-related syndrome.
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29
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Yigit G, Sheffer R, Daana M, Li Y, Kaygusuz E, Mor-Shakad H, Altmüller J, Nürnberg P, Douiev L, Kaulfuss S, Burfeind P, Wollnik B, Brockmann K. Loss-of-function variants in DNM1 cause a specific form of developmental and epileptic encephalopathy only in biallelic state. J Med Genet 2021; 59:549-553. [PMID: 34172529 PMCID: PMC9132866 DOI: 10.1136/jmedgenet-2021-107769] [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: 02/17/2021] [Accepted: 05/08/2021] [Indexed: 11/23/2022]
Abstract
Background Developmental and epileptic encephalopathies (DEEs) represent a group of severe neurological disorders characterised by an onset of refractory seizures during infancy or early childhood accompanied by psychomotor developmental delay or regression. DEEs are genetically heterogeneous with, to date, more than 80 different genetic subtypes including DEE31 caused by heterozygous missense variants in DNM1. Methods We performed a detailed clinical characterisation of two unrelated patients with DEE and used whole-exome sequencing to identify causative variants in these individuals. The identified variants were tested for cosegregation in the respective families. Results We excluded pathogenic variants in known, DEE-associated genes. We identified homozygous nonsense variants, c.97C>T; p.(Gln33*) in family 1 and c.850C>T; p.(Gln284*) in family 2, in the DNM1 gene, indicating that biallelic, loss-of-function pathogenic variants in DNM1 cause DEE. Conclusion Our finding that homozygous, loss-of-function variants in DNM1 cause DEE expands the spectrum of pathogenic variants in DNM1. All parents who were heterozygous carriers of the identified loss-of-function variants were healthy and did not show any clinical symptoms, indicating that the type of mutation in DNM1 determines the pattern of inheritance.
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Affiliation(s)
- Gökhan Yigit
- Institute of Human Genetics, University Medical Center Göttingen, Gottingen, Germany
| | - Ruth Sheffer
- Department of Human Genetics, Hadassah University Hospital, Jerusalem, Israel
| | - Muhannad Daana
- Child Development Institute, Clalit Health Services, Tel Aviv, Israel
| | - Yun Li
- Institute of Human Genetics, University Medical Center Göttingen, Gottingen, Germany
| | - Emrah Kaygusuz
- Institute of Human Genetics, University Medical Center Göttingen, Gottingen, Germany.,Molecular Biology and Genetics, Bilecik Şeyh Edebali University, Bilecik, Turkey
| | - Hagar Mor-Shakad
- Department of Human Genetics, Hadassah University Hospital, Jerusalem, Israel
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Liza Douiev
- Department of Human Genetics, Hadassah University Hospital, Jerusalem, Israel
| | - Silke Kaulfuss
- Institute of Human Genetics, University Medical Center Göttingen, Gottingen, Germany
| | - Peter Burfeind
- Institute of Human Genetics, University Medical Center Göttingen, Gottingen, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Göttingen, Gottingen, Germany .,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Gottingen, Gottingen, Germany
| | - Knut Brockmann
- Interdisciplinary Pediatric Center for Children with Developmental Disabilities and Severe Chronic Disorders, University Medical Center Göttingen, Gottingen, Germany
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30
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Kang Q, Yang L, Liao H, Yang S, Kuang X, Ning Z, Liao C, Chen B. A Chinese patient with developmental and epileptic encephalopathies (DEE) carrying a TRPM3 gene mutation: a paediatric case report. BMC Pediatr 2021; 21:256. [PMID: 34074259 PMCID: PMC8167971 DOI: 10.1186/s12887-021-02719-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 05/18/2021] [Indexed: 11/11/2022] Open
Abstract
Background Developmental and epileptic encephalopathies (DEEs) are a heterogeneous group of chronic encephalopathies characterized by epilepsy with comorbid intellectual disability that are frequently associated with de novo nonsynonymous coding variants in ion channels, cell-surface receptors, and other neuronally expressed genes. Mutations in TRPM3 were identified as the cause of DEE. We report a novel patient with DEE carrying a de novo missense mutation in TRPM3, p.(S1202T); this missense mutation has never been reported. Case presentation A 7-year and 2-month-old Chinese patient who had recurrent polymorphic seizures was clinically diagnosed with DEE. A de novo missense mutation in TRPM3, which has not yet been reported, was identified in this case. The patient had a clinical phenotype consistent with previous reports. Conclusions These findings could expand the spectrum of TRPM3 mutations and might also support that de novo substitutions of TRPM3 are a cause of DEE.
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Affiliation(s)
- Qingyun Kang
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China
| | - Liming Yang
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China
| | - Hongmei Liao
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China
| | - Sai Yang
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China
| | - Xiaojun Kuang
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China
| | - Zeshu Ning
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China
| | - Caishi Liao
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China
| | - Bo Chen
- Department of Neurology, Hunan Children's Hospital, No.86 Ziyuan Road, Changsha, 410007, Hunan, People's Republic of China.
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31
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Fonseca J, Melo C, Ferreira C, Sampaio M, Sousa R, Leão M. RHOBTB2 p.Arg511Trp Mutation in Early Infantile Epileptic Encephalopathy-64: Review and Case Report. J Pediatr Genet 2021; 12:155-158. [PMID: 37090824 PMCID: PMC10118705 DOI: 10.1055/s-0040-1722288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 11/23/2020] [Indexed: 10/22/2022]
Abstract
AbstractEarly infantile epileptic encephalopathy-64 (EIEE 64), also called RHOBTB2-related developmental and epileptic encephalopathy (DEE), is caused by heterozygous pathogenic variants (EIEE 64; MIM#618004) in the Rho-related BTB domain-containing protein 2 (RHOBTB2) gene. To date, only 13 cases with RHOBTB2-related DEE have been reported. We add to the literature the 14th case of EIEE 64, identified by whole exome sequencing, caused by a heterozygous pathogenic variant in RHOBTB2 (c.1531C > T), p.Arg511Trp. This additional case supports the main features of RHOBTB2-related DEE: infantile-onset seizures, severe intellectual disability, impaired motor functions, postnatal microcephaly, recurrent status epilepticus, and hemiparesis after seizures.
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Affiliation(s)
- J Fonseca
- Pediatric Neurology Unit, Department of Pediatric, Centro Hospitalar Universitário de São João, Porto, Portugal
| | - C Melo
- Pediatric Neurology Unit, Department of Pediatric, Centro Hospitalar Universitário de São João, Porto, Portugal
| | - C Ferreira
- Department of Ophthalmology, Centro Hospitalar Vila Nova Gaia/Espinho, Espinho, Portugal
| | - M Sampaio
- Pediatric Neurology Unit, Department of Pediatric, Centro Hospitalar Universitário de São João, Porto, Portugal
| | - R Sousa
- Pediatric Neurology Unit, Department of Pediatric, Centro Hospitalar Universitário de São João, Porto, Portugal
| | - M Leão
- Neurogenetics Unit, Department of Medical Genetics, Centro Hospitalar Universitário de São João, Porto, Portugal
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Lamar KMJ, Carvill GL. Free as a BRD4: Bromodomain Inhibition Ameliorates Disease Phenotypes in a Model of MECP2 Deficiency and Is a Potential Therapy for Rett Syndrome. Epilepsy Curr 2020; 20:390-392. [PMID: 34025262 PMCID: PMC7818197 DOI: 10.1177/1535759720960469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Dysregulation of BRD4 Function Underlies the Functional Abnormalities of MeCP2 Mutant Neurons Xiang Y, Tanaka Y, Patterson B, et al. Mole Cell . 2020;79(1):84-98. e9. doi:10.1016/j.molcel.2020.05.016 Rett syndrome (RTT), mainly caused by mutations in methyl-CpG binding protein 2 (MeCP2), is one of the most prevalent intellectual disorders without effective therapies. Here, we used 2D and 3D human brain cultures to investigate MeCP2 function. We found that MeCP2 mutations cause severe abnormalities in human interneurons (INs). Surprisingly, treatment with a BET inhibitor, JQ1, rescued the molecular and functional phenotypes of MeCP2 mutant INs. We uncovered that abnormal increases in chromatin binding of BRD4 and enhancer-promoter interactions underlie the abnormal transcription in MeCP2 mutant INs, which were recovered to normal levels by JQ1. We revealed cell-type-specific transcriptome impairment in MeCP2 mutant region-specific human brain organoids that were rescued by JQ1. Finally, JQ1 ameliorated RTT-like phenotypes in mice. These data demonstrate that BRD4 dysregulation is a critical driver for RTT etiology and suggest that targeting BRD4 could be a potential therapeutic opportunity for RTT.
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Affiliation(s)
| | - Gemma L Carvill
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Takai A, Yamaguchi M, Yoshida H, Chiyonobu T. Investigating Developmental and Epileptic Encephalopathy Using Drosophila melanogaster. Int J Mol Sci 2020; 21:ijms21176442. [PMID: 32899411 PMCID: PMC7503973 DOI: 10.3390/ijms21176442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/30/2020] [Accepted: 09/01/2020] [Indexed: 12/16/2022] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are the spectrum of severe epilepsies characterized by early-onset, refractory seizures occurring in the context of developmental regression or plateauing. Early infantile epileptic encephalopathy (EIEE) is one of the earliest forms of DEE, manifesting as frequent epileptic spasms and characteristic electroencephalogram findings in early infancy. In recent years, next-generation sequencing approaches have identified a number of monogenic determinants underlying DEE. In the case of EIEE, 85 genes have been registered in Online Mendelian Inheritance in Man as causative genes. Model organisms are indispensable tools for understanding the in vivo roles of the newly identified causative genes. In this review, we first present an overview of epilepsy and its genetic etiology, especially focusing on EIEE and then briefly summarize epilepsy research using animal and patient-derived induced pluripotent stem cell (iPSC) models. The Drosophila model, which is characterized by easy gene manipulation, a short generation time, low cost and fewer ethical restrictions when designing experiments, is optimal for understanding the genetics of DEE. We therefore highlight studies with Drosophila models for EIEE and discuss the future development of their practical use.
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Affiliation(s)
- Akari Takai
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan;
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan; (M.Y.); (H.Y.)
- Kansai Gakken Laboratory, Kankyo Eisei Yakuhin Co. Ltd., Kyoto 619-0237, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 603-8585, Japan; (M.Y.); (H.Y.)
| | - Tomohiro Chiyonobu
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan;
- Correspondence:
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Wayhelova M, Ryzí M, Oppelt J, Hladilkova E, Vallova V, Krskova L, Vilemova M, Polackova H, Gaillyova R, Kuglik P. Novel familial IQSEC2 pathogenic sequence variant associated with neurodevelopmental disorders and epilepsy. Neurogenetics 2020; 21:269-278. [PMID: 32564198 DOI: 10.1007/s10048-020-00616-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 05/11/2020] [Indexed: 01/22/2023]
Abstract
Pathogenic sequence variants in the IQ motif- and Sec7 domain-containing protein 2 (IQSEC2) gene have been confirmed as causative in the aetiopathogenesis of neurodevelopmental disorders (intellectual disability, autism) and epilepsy. We report on a case of a family with three sons; two of them manifest delayed psychomotor development and epilepsy. Initially proband A was examined using a multistep molecular diagnostics algorithm, including karyotype and array-comparative genomic hybridization analysis, both with negative results. Therefore, probands A and B and their unaffected parents were enrolled for an analysis using targeted "next-generation" sequencing (NGS) with a gene panel ClearSeq Inherited DiseaseXT (Agilent Technologies) and verification analysis by Sanger sequencing. A novel frameshift variant in the X-linked IQSEC2 gene NM_001111125.2:c.1813_1814del, p.(Asp605Profs*3) on protein level, was identified in both affected probands and their asymptomatic mother, having skewed X chromosome inactivation (XCI) (100:0). As the IQSEC2 gene is a known gene escaping from XCI in humans, we expect the existence of mechanisms maintaining the normal or enough level of the IQSEC2 protein in the asymptomatic mother. Further analyses may help to the characterization of the presented novel frameshift variant in the IQSEC2 gene as well as to elucidate the mechanisms leading to the rare asymptomatic phenotypes in females.
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Affiliation(s)
- Marketa Wayhelova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.,Department of Medical Genetics, University Hospital Brno, Brno, Czech Republic
| | - Michal Ryzí
- Clinic of Children's Neurology, University Hospital Brno, Brno, Czech Republic
| | - Jan Oppelt
- CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Eva Hladilkova
- Department of Medical Genetics, University Hospital Brno, Brno, Czech Republic
| | - Vladimira Vallova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.,Department of Medical Genetics, University Hospital Brno, Brno, Czech Republic
| | - Lenka Krskova
- Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, Prague, Czech Republic
| | - Marcela Vilemova
- Department of Medical Genetics, University Hospital Brno, Brno, Czech Republic
| | - Hana Polackova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Renata Gaillyova
- Department of Medical Genetics, University Hospital Brno, Brno, Czech Republic
| | - Petr Kuglik
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic. .,Department of Medical Genetics, University Hospital Brno, Brno, Czech Republic.
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