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Scheffer IE, Zuberi S, Mefford HC, Guerrini R, McTague A. Developmental and epileptic encephalopathies. Nat Rev Dis Primers 2024; 10:61. [PMID: 39237642 DOI: 10.1038/s41572-024-00546-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/29/2024] [Indexed: 09/07/2024]
Abstract
Developmental and epileptic encephalopathies, the most severe group of epilepsies, are characterized by seizures and frequent epileptiform activity associated with developmental slowing or regression. Onset typically occurs in infancy or childhood and includes many well-defined epilepsy syndromes. Patients have wide-ranging comorbidities including intellectual disability, psychiatric features, such as autism spectrum disorder and behavioural problems, movement and musculoskeletal disorders, gastrointestinal and sleep problems, together with an increased mortality rate. Problems change with age and patients require substantial support throughout life, placing a high psychosocial burden on parents, carers and the community. In many patients, the aetiology can be identified, and a genetic cause is found in >50% of patients using next-generation sequencing technologies. More than 900 genes have been identified as monogenic causes of developmental and epileptic encephalopathies and many cell components and processes have been implicated in their pathophysiology, including ion channels and transporters, synaptic proteins, cell signalling and metabolism and epigenetic regulation. Polygenic risk score analyses have shown that common variants also contribute to phenotypic variability. Holistic management, which encompasses antiseizure therapies and care for multimorbidities, is determined both by epilepsy syndrome and aetiology. Identification of the underlying aetiology enables the development of precision medicines to improve the long-term outcome of patients with these devastating diseases.
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Affiliation(s)
- Ingrid E Scheffer
- Epilepsy Research Centre, The University of Melbourne, Austin Health, Heidelberg, Victoria, Australia.
- Florey and Murdoch Children's Research Institutes, Melbourne, Victoria, Australia.
- Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia.
| | - Sameer Zuberi
- Paediatric Neurosciences Research Group, School of Health & Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences, Royal Hospital for Children, Glasgow, UK
| | - Heather C Mefford
- Center for Paediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Meyer IRCCS, Florence, Italy
- University of Florence, Florence, Italy
| | - Amy McTague
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
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Gallagher D, Pérez-Palma E, Bruenger T, Ghanty I, Brilstra E, Ceulemans B, Chemaly N, de Lange I, Depienne C, Guerrini R, Mei D, Møller RS, Nabbout R, Regan BM, Schneider AL, Scheffer IE, Schoonjans AS, Symonds JD, Weckhuysen S, Zuberi SM, Lal D, Brunklaus A. Genotype-phenotype associations in 1018 individuals with SCN1A-related epilepsies. Epilepsia 2024; 65:1046-1059. [PMID: 38410936 DOI: 10.1111/epi.17882] [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: 09/17/2023] [Revised: 12/30/2023] [Accepted: 01/03/2024] [Indexed: 02/28/2024]
Abstract
OBJECTIVE SCN1A variants are associated with epilepsy syndromes ranging from mild genetic epilepsy with febrile seizures plus (GEFS+) to severe Dravet syndrome (DS). Many variants are de novo, making early phenotype prediction difficult, and genotype-phenotype associations remain poorly understood. METHODS We assessed data from a retrospective cohort of 1018 individuals with SCN1A-related epilepsies. We explored relationships between variant characteristics (position, in silico prediction scores: Combined Annotation Dependent Depletion (CADD), Rare Exome Variant Ensemble Learner (REVEL), SCN1A genetic score), seizure characteristics, and epilepsy phenotype. RESULTS DS had earlier seizure onset than other GEFS+ phenotypes (5.3 vs. 12.0 months, p < .001). In silico variant scores were higher in DS versus GEFS+ (p < .001). Patients with missense variants in functionally important regions (conserved N-terminus, S4-S6) exhibited earlier seizure onset (6.0 vs. 7.0 months, p = .003) and were more likely to have DS (280/340); those with missense variants in nonconserved regions had later onset (10.0 vs. 7.0 months, p = .036) and were more likely to have GEFS+ (15/29, χ2 = 19.16, p < .001). A minority of protein-truncating variants were associated with GEFS+ (10/393) and more likely to be located in the proximal first and last exon coding regions than elsewhere in the gene (9.7% vs. 1.0%, p < .001). Carriers of the same missense variant exhibited less variability in age at seizure onset compared with carriers of different missense variants for both DS (1.9 vs. 2.9 months, p = .001) and GEFS+ (8.0 vs. 11.0 months, p = .043). Status epilepticus as presenting seizure type is a highly specific (95.2%) but nonsensitive (32.7%) feature of DS. SIGNIFICANCE Understanding genotype-phenotype associations in SCN1A-related epilepsies is critical for early diagnosis and management. We demonstrate an earlier disease onset in patients with missense variants in important functional regions, the occurrence of GEFS+ truncating variants, and the value of in silico prediction scores. Status epilepticus as initial seizure type is a highly specific, but not sensitive, early feature of DS.
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Affiliation(s)
- Declan Gallagher
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eduardo Pérez-Palma
- Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Santiago, Chile
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Tobias Bruenger
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Ismael Ghanty
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Eva Brilstra
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Berten Ceulemans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Nicole Chemaly
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Iris de Lange
- Department of Genetics, University Medical Center, Utrecht, the Netherlands
| | - Christel Depienne
- Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Davide Mei
- Neuroscience Department, Children's Hospital A. Meyer Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) and University of Florence, Florence, Italy
| | - Rikke S Møller
- Danish Epilepsy Center, Filadelfia, Dianalund, Denmark
- Department of Regional Health Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Rima Nabbout
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Hôpital Necker-Enfants Malades, Université de Paris, Paris, France
| | - Brigid M Regan
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Amy L Schneider
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Ingrid E Scheffer
- Department of Medicine, Epilepsy Research Centre, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
- University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Victoria, Australia
| | - An-Sofie Schoonjans
- Department of Child Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - Joseph D Symonds
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Sarah Weckhuysen
- Applied & Translational Neurogenomics Group, VIB Center for Molecular Neurology, Antwerp, Belgium
- Neurology Department, University Hospital Antwerp, Antwerp, Belgium
- Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Sameer M Zuberi
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
| | - Dennis Lal
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, USA
- Stanley Center for Psychiatric Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Department of Neurology, McGovern Medical School, UTHealth Houston, Houston, Texas, USA
| | - Andreas Brunklaus
- School of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, UK
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Zeng B, Zhang H, Lu Q, Fu Q, Yan Y, Lu W, Ma P, Feng C, Qin J, Luo L, Yang B, Zou Y, Liu Y. Identification of five novel SCN1A variants. Front Behav Neurosci 2023; 17:1272748. [PMID: 38025388 PMCID: PMC10663289 DOI: 10.3389/fnbeh.2023.1272748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Background Epilepsy is characterized by recurrent unprovoked seizures. Mutations in the voltage-gated sodium channel alpha subunit 1 (SCN1A) gene are the main monogenic cause of epilepsy. Type and location of variants make a huge difference in the severity of SCN1A disorder, ranging from the mild phenotype (genetic epilepsy with febrile seizures plus, GEFS+) to the severe phenotype (developmental and epileptic encephalopathies, DEEs). Dravet Syndrome (DS) is an infantile-onset DEE, characterized by drug-resistant epilepsy and temperature sensitivity or febrile seizures. Genetic test results reveal SCN1A variants are positive in 80% DS patients and DS is mainly caused by de novo variants. Methods Trio-whole exome sequencing (WES) was used to detect variants which were associated with clinical phenotype of five probands with epilepsy or twitching. Then, Sanger sequencing was performed to validate the five novel SCN1A variants and segregation analysis. After analyzing the location of five SCN1A variants, the pathogenic potential was assessed. Results In this study, we identified five novel SCN1A variants (c.4224G > C, c.3744_3752del, c.209del, c.5727_5734delTTTAAAACinsCTTAAAAAG and c.5776delT) as the causative variants. In the five novel SCN1A variants, four were de novo and the remaining one was inherited. All novel variants would be classified as "pathogenic" or "likely pathogenic." Conclusion The five novel SCN1A variants will enrich the SCN1A mutations database and provide the corresponding reference data for the further genetic counseling.
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Affiliation(s)
- Baitao Zeng
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Haoyi Zhang
- School of Public Health, Nanchang University, Nanchang, China
| | - Qing Lu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Qingzi Fu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Yang Yan
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Wan Lu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Pengpeng Ma
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Chuanxin Feng
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Jiawei Qin
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Laipeng Luo
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Bicheng Yang
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Yongyi Zou
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Yanqiu Liu
- Department of Medical Genetics, Jiangxi Maternal and Child Health Hospital, Nanchang, China
- Jiangxi Provincial Key Laboratory of Birth Defect for Prevention and Control, Jiangxi Maternal and Child Health Hospital, Nanchang, China
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Martins Custodio H, Clayton LM, Bellampalli R, Pagni S, Silvennoinen K, Caswell R, Brunklaus A, Guerrini R, Koeleman BPC, Lemke JR, Møller RS, Scheffer IE, Weckhuysen S, Zara F, Zuberi S, Kuchenbaecker K, Balestrini S, Mills JD, Sisodiya SM. Widespread genomic influences on phenotype in Dravet syndrome, a 'monogenic' condition. Brain 2023; 146:3885-3897. [PMID: 37006128 PMCID: PMC10473570 DOI: 10.1093/brain/awad111] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 02/01/2023] [Accepted: 03/12/2023] [Indexed: 04/04/2023] Open
Abstract
Dravet syndrome is an archetypal rare severe epilepsy, considered 'monogenic', typically caused by loss-of-function SCN1A variants. Despite a recognizable core phenotype, its marked phenotypic heterogeneity is incompletely explained by differences in the causal SCN1A variant or clinical factors. In 34 adults with SCN1A-related Dravet syndrome, we show additional genomic variation beyond SCN1A contributes to phenotype and its diversity, with an excess of rare variants in epilepsy-related genes as a set and examples of blended phenotypes, including one individual with an ultra-rare DEPDC5 variant and focal cortical dysplasia. The polygenic risk score for intelligence was lower, and for longevity, higher, in Dravet syndrome than in epilepsy controls. The causal, major-effect, SCN1A variant may need to act against a broadly compromised genomic background to generate the full Dravet syndrome phenotype, whilst genomic resilience may help to ameliorate the risk of premature mortality in adult Dravet syndrome survivors.
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Affiliation(s)
- Helena Martins Custodio
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Lisa M Clayton
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Ravishankara Bellampalli
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Susanna Pagni
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Katri Silvennoinen
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Kuopio Epilepsy Center, Neurocenter, Kuopio University Hospital, Kuopio 70210, Finland
| | - Richard Caswell
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Andreas Brunklaus
- Paediatric Neuroscience Research Group, Royal Hospital for Children, Glasgow G51 4TF, UK
- Institute of Health and Wellbeing, University of Glasgow, Glasgow G12 8TB, UK
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children’s Hospital IRCSS, University of Florence, 50139 Florence, Italy
| | - Bobby P C Koeleman
- Department of Genetics, University Medical Centre Utrecht, 3584CX Utrecht, The Netherlands
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig 04103, Germany
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, DK-4293 Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Florey Institute, University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC 3084, Australia
- Murdoch Children's Research Institute, Parkville, VIC 3052, Australia
| | - Sarah Weckhuysen
- Applied and Translational Neurogenomics Group, VIB Centre for Molecular Neurology, VIB, Antwerp 2610, Belgium
- Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp 2650, Belgium
- Department of Neurology, University Hospital Antwerp, Antwerp 2650, Belgium
- µNEURO Research Centre of Excellence, University of Antwerp, Antwerp 2610, Belgium
| | - Federico Zara
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy
- Department of Neurosciences Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
| | - Sameer Zuberi
- Paediatric Neuroscience Research Group, Royal Hospital for Children, Glasgow G51 4TF, UK
- Institute of Health and Wellbeing, University of Glasgow, Glasgow G12 8TB, UK
| | | | - Simona Balestrini
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Neuroscience Department, Meyer Children’s Hospital IRCSS, University of Florence, 50139 Florence, Italy
| | - James D Mills
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, 1105 AZ Amsterdam, The Netherlands
| | - Sanjay M Sisodiya
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
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Pagni S, Custodio HM, Frankish A, Mudge JM, Mills JD, Sisodiya SM. SCN1A: bioinformatically informed revised boundaries for promoter and enhancer regions. Hum Mol Genet 2023; 32:1753-1763. [PMID: 36715146 PMCID: PMC10162429 DOI: 10.1093/hmg/ddad015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/06/2023] [Accepted: 01/24/2023] [Indexed: 01/31/2023] Open
Abstract
Pathogenic variations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene are responsible for multiple epilepsy phenotypes, including Dravet syndrome, febrile seizures (FS) and genetic epilepsy with FS plus. Phenotypic heterogeneity is a hallmark of SCN1A-related epilepsies, the causes of which are yet to be clarified. Genetic variation in the non-coding regulatory regions of SCN1A could be one potential causal factor. However, a comprehensive understanding of the SCN1A regulatory landscape is currently lacking. Here, we summarized the current state of knowledge of SCN1A regulation, providing details on its promoter and enhancer regions. We then integrated currently available data on SCN1A promoters by extracting information related to the SCN1A locus from genome-wide repositories and clearly defined the promoter and enhancer regions of SCN1A. Further, we explored the cellular specificity of differential SCN1A promoter usage. We also reviewed and integrated the available human brain-derived enhancer databases and mouse-derived data to provide a comprehensive computationally developed summary of SCN1A brain-active enhancers. By querying genome-wide data repositories, extracting SCN1A-specific data and integrating the different types of independent evidence, we created a comprehensive catalogue that better defines the regulatory landscape of SCN1A, which could be used to explore the role of SCN1A regulatory regions in disease.
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Affiliation(s)
- Susanna Pagni
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Bucks SL9 0RJ, UK
| | - Helena Martins Custodio
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Bucks SL9 0RJ, UK
| | - Adam Frankish
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, UK
| | - Jonathan M Mudge
- European Molecular Biology Laboratory, European Bioinformatics Institute, Cambridge, UK
| | - James D Mills
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Bucks SL9 0RJ, UK
- Amsterdam UMC, Department of (Neuro) Pathology, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, 1105 AZ The Netherlands
| | - Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Bucks SL9 0RJ, UK
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Exploring the Genetic Causality of Discordant Phenotypes in Familial Apparently Balanced Translocation Cases Using Whole Exome Sequencing. Genes (Basel) 2022; 14:genes14010082. [PMID: 36672823 PMCID: PMC9859009 DOI: 10.3390/genes14010082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022] Open
Abstract
Familial apparently balanced translocations (ABTs) are usually not associated with a phenotype; however, rarely, ABTs segregate with discordant phenotypes in family members carrying identical rearrangements. The current study was a follow-up investigation of four familial ABTs, where whole exome sequencing (WES) was implemented as a diagnostic tool to identify the underlying genetic aetiology of the patients' phenotypes. Data were analysed using an in-house bioinformatics pipeline alongside VarSome Clinical. WES findings were validated with Sanger sequencing, while the impact of splicing and missense variants was assessed by reverse-transcription PCR and in silico tools, respectively. Novel candidate variants were identified in three families. In family 1, it was shown that the de novo pathogenic STXBP1 variant (NM_003165.6:c.1110+2T>G) affected splicing and segregated with the patient's phenotype. In family 2, a likely pathogenic TUBA1A variant (NM_006009.4:c.875C>T, NP_006000.2:p.(Thr292Ile)) could explain the patient's symptoms. In family 3, an SCN1A variant of uncertain significance (NM_006920.6:c.5060A>G, NP_008851.3:p.(Glu1687Gly)) required additional evidence to sufficiently support causality. This first report of WES application in familial ABT carriers with discordant phenotypes supported our previous findings describing such rearrangements as coincidental. Thus, WES can be recommended as a complementary test to find the monogenic cause of aberrant phenotypes in familial ABT carriers.
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Chen Y, Yang X, Chen J, Yang X, Yang Y, Liu A, Zhang X, Wu W, Sun D, Yang Z, Jiang Y, Zhang Y. PCDH19-related epilepsy in mosaic males: The phenotypic implication of genotype and variant allele frequency. Front Neurol 2022; 13:1041509. [PMID: 36408521 PMCID: PMC9669318 DOI: 10.3389/fneur.2022.1041509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/06/2022] [Indexed: 11/15/2023] Open
Abstract
OBJECTIVE To analyze the genotypes and phenotypes of mosaic male patients with PCDH19-related epilepsy (PCDH19-RE) and explore the correlation between genotype, variant allele frequency (VAF), and phenotypic severity. METHODS Clinical data and peripheral blood samples of 11 male mosaic patients were collected and analyzed in our study. The VAF of the PCDH19 gene from peripheral blood was quantified using amplicon-based deep sequencing. Additional 20 mosaic male patients with PCDH19-RE were collected from the published literature, with 10 patients whose VAFs of the PCDH19 gene were available for analytic purposes. RESULTS In our cohort of 11 patients, 10 variants were identified, and four were novel. The VAF of the PCDH19 gene from peripheral blood ranged from 27 to 90%. The median seizure onset age was 6 months (range: 4-9 months). Clinical manifestations included cluster seizures (100%), fever sensitivity (73%), focal seizures (91%), developmental delay/intellectual disability (DD/ID, 82%), and autistic features (45%). Thirty-one mosaic male patients collected from our cohort and the literature developed seizures mostly (87%) within one year of age. Variant types included missense variants (42%), truncating variants (52%), splice variants (3%), and whole PCDH19 deletion (3%). Among 21 patients with a definite VAF from our cohort and the literature, nine had a low VAF ( ≤ 50%) and 12 had a high VAF (> 50%). Seventy-five percent of variants from the high VAF group were missense, whereas 89% of those from the low VAF group were truncations. The median seizure onset age was 6 months in the low VAF group and 9 months in the high VAF group (p = 0.018). Forty-four percent (4/9) of patients from the low VAF group achieved seizure-free for ≥1 year, whereas none of the 12 patients from the high VAF group did (p = 0.021). DD/ID was present in 83% (10/12) of the high VAF group and 56% (5/9) of the low VAF group (p = 0.331). CONCLUSION The predominant variant types were truncating and missense variants. Missense variants tended to have higher VAFs. Patients with a high VAF were more likely to have a more severe epileptic phenotype. Our findings shed light on the phenotypic implications of VAF in mosaic males with PCDH19-RE.
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Affiliation(s)
- Yi Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoxu Yang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, China
| | - Jiaoyang Chen
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xiaoling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ying Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Aijie Liu
- Department of Pediatric Neurology, Capital Institute of Pediatrics, Beijing, China
| | - Xiaoli Zhang
- Department of Pediatrics, The Third Affiliated Hospital of Zheng Zhou University, Zhengzhou, China
| | - Wenjuan Wu
- Department of Neurology, Hebei Children's Hospital, Shijiazhuang, China
| | - Dan Sun
- Department of Neurology, Wuhan Children's Hospital, Wuhan, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
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He Z, Li Y, Zhao X, Li B. Dravet Syndrome: Advances in Etiology, Clinical Presentation, and Treatment. Epilepsy Res 2022; 188:107041. [DOI: 10.1016/j.eplepsyres.2022.107041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/08/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022]
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Fang Z, Xie L, Li X, Gui J, Yang X, Han Z, Luo H, Huang D, Chen H, Cheng L, Jiang L. Severe epilepsy phenotype with SCN1A missense variants located outside the sodium channel core region: Relationship between functional results and clinical phenotype. Seizure 2022; 101:109-116. [PMID: 35944423 DOI: 10.1016/j.seizure.2022.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/17/2022] [Accepted: 07/29/2022] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Most SCN1A missense variants located outside the sodium channel core region show a mild phenotype. However, there are exceptions, because of which it is challenging to determine the correlation between genotype and phenotype. In this study, we aimed to determine whether functional study could be used to determine disease severity in cases with such variants, and elucidate possible genotype-phenotype relationships. METHODS Forty-seven patients with SCN1A missense variants were recruited, and one with a Dravet syndrome phenotype with an SCN1A missense variant (c.3811T>C/ p.W1271R) located outside the core region was screened with electrophysiological tests. We also reviewed functional SCN1A studies on patients with inconsistent phenotypes and genotypes, and studied the relationship between electrophysiological measurements and clinical phenotype. RESULTS Patch clamp experiments showed that the W1271R variant caused significantly reduced sodium current, decreased channel voltage sensitivity, loss of channel availability, and prolonged recovery time from inactivation compared with wild type (WT), which ultimately caused a change in loss of function (LOF). Twelve cases of severe SCN1A-related epilepsy with missense variants located outside the channel core region were also included from the functional studies. Nine patients with missense SCN1A variants showed complete (3/9) or partial (6/9) physiological LOF. Two missense SCN1A variants caused physiological gain-and-loss of function (G-LOF), and one caused decreased excitability (DE). CONCLUSIONS Not all missense variants located outside the core region cause a mild phenotype. Although current functional studies in heterologous expression systems do not accurately reflect disease severity caused by SCN1A missense variants, they could be an effective model for generation of data to study the initial effects of SCN1A missense variants.
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Affiliation(s)
- Zhixu Fang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Lingling Xie
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Xue Li
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Jianxiong Gui
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Xiaoyue Yang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Ziyao Han
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Hanyu Luo
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Dishu Huang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Hengsheng Chen
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Li Cheng
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China
| | - Li Jiang
- Department of Neurology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, No. 136, Zhongshan Er Road, Yuzhong District, Chongqing 400014, China.
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Genetic therapeutic advancements for Dravet Syndrome. Epilepsy Behav 2022; 132:108741. [PMID: 35653814 DOI: 10.1016/j.yebeh.2022.108741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 11/03/2022]
Abstract
Dravet Syndrome is a genetic epileptic syndrome characterized by severe and intractable seizures associated with cognitive, motor, and behavioral impairments. The disease is also linked with increased mortality mainly due to sudden unexpected death in epilepsy. Over 80% of cases are due to a de novo mutation in one allele of the SCN1A gene, which encodes the α-subunit of the voltage-gated ion channel NaV1.1. Dravet Syndrome is usually refractory to antiepileptic drugs, which only alleviate seizures to a small extent. Viral, non-viral genetic therapy, and gene editing tools are rapidly enhancing and providing new platforms for more effective, alternative medicinal treatments for Dravet syndrome. These strategies include gene supplementation, CRISPR-mediated transcriptional activation, and the use of antisense oligonucleotides. In this review, we summarize our current knowledge of novel genetic therapies that are currently under development for Dravet syndrome.
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Genetics and gene therapy in Dravet syndrome. Epilepsy Behav 2022; 131:108043. [PMID: 34053869 DOI: 10.1016/j.yebeh.2021.108043] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 05/02/2021] [Accepted: 05/02/2021] [Indexed: 12/17/2022]
Abstract
Dravet syndrome is a well-established electro-clinical condition first described in 1978. A main genetic cause was identified with the discovery of a loss-of-function SCN1A variant in 2001. Mechanisms underlying the phenotypic variations have subsequently been a main topic of research. Various genetic modifiers of clinical severities have been elucidated through many rigorous studies on genotype-phenotype correlations and the recent advances in next generation sequencing technology. Furthermore, a deeper understanding of the regulation of gene expression and remarkable progress on genome-editing technology using the CRISPR-Cas9 system provide significant opportunities to overcome hurdles of gene therapy, such as enhancing NaV1.1 expression. This article reviews the current understanding of genetic pathology and the status of research toward the development of gene therapy for Dravet syndrome. This article is part of the Special Issue "Severe Infantile Epilepsies".
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Marco-Hernández AV, Caro-Llopis A, Rubio Sánchez P, Martínez Martínez JC, Tomás Vila M, Monfort S, Martínez F. Extending the Phenotype Related to SCN1A Gene: Arthrogryposis, Movement Disorders, and Malformations of Cortical Development. J Child Neurol 2022; 37:340-350. [PMID: 35072530 DOI: 10.1177/08830738211072694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Expand the knowledge about the clinical phenotypes associated with pathogenic or likely pathogenic variants in the SCN1A gene. METHODS The study was carried out in 15 patients with SCN1A variants. The complete phenotype of the patients was evaluated. A systematic search was carried out in the scientific literature for those unexpected symptoms. RESULTS Ten patients showed a missense variant, whereas the remaining showed different loss-of-function variants. Twelve (80%) had Dravet syndrome. Two (13.3%) had Epilepsy with febrile seizures plus. Three (20%) presented an atypical phenotype. One of them was developmental and epileptic encephalopathy with arthrogryposis, the other Dravet syndrome and movement disorder, and lastly one patient had Dravet syndrome and malformations of the cortical development. CONCLUSION The exhaustive assessment of patients with pathogenic alterations detected in massive sequencing can help us to expand the phenotype, understand the etiopathogenesis associated with each genetic abnormality, and thus improve the prognosis and management of future patients.
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Affiliation(s)
| | | | - Pilar Rubio Sánchez
- Neurophysiology Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | | | - Miguel Tomás Vila
- Neuropediatric Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Sandra Monfort
- Genetics Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Francisco Martínez
- Genetics Unit, Hospital Universitario y Politécnico La Fe, Valencia, Spain
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Brunklaus A, Pérez-Palma E, Ghanty I, Xinge J, Brilstra E, Ceulemans B, Chemaly N, de Lange I, Depienne C, Guerrini R, Mei D, Møller RS, Nabbout R, Regan BM, Schneider AL, Scheffer IE, Schoonjans AS, Symonds JD, Weckhuysen S, Kattan MW, Zuberi SM, Lal D. Development and Validation of a Prediction Model for Early Diagnosis of SCN1A-Related Epilepsies. Neurology 2022; 98:e1163-e1174. [PMID: 35074891 PMCID: PMC8935441 DOI: 10.1212/wnl.0000000000200028] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 01/03/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Pathogenic variants in the neuronal sodium channel α1 subunit gene (SCN1A) are the most frequent monogenic cause of epilepsy. Phenotypes comprise a wide clinical spectrum, including severe childhood epilepsy; Dravet syndrome, characterized by drug-resistant seizures, intellectual disability, and high mortality; and the milder genetic epilepsy with febrile seizures plus (GEFS+), characterized by normal cognition. Early recognition of a child's risk for developing Dravet syndrome vs GEFS+ is key for implementing disease-modifying therapies when available before cognitive impairment emerges. Our objective was to develop and validate a prediction model using clinical and genetic biomarkers for early diagnosis of SCN1A-related epilepsies. METHODS We performed a retrospective multicenter cohort study comprising data from patients with SCN1A-positive Dravet syndrome and patients with GEFS+ consecutively referred for genetic testing (March 2001-June 2020) including age at seizure onset and a newly developed SCN1A genetic score. A training cohort was used to develop multiple prediction models that were validated using 2 independent blinded cohorts. Primary outcome was the discriminative accuracy of the model predicting Dravet syndrome vs other GEFS+ phenotypes. RESULTS A total of 1,018 participants were included. The frequency of Dravet syndrome was 616/743 (83%) in the training cohort, 147/203 (72%) in validation cohort 1, and 60/72 (83%) in validation cohort 2. A high SCN1A genetic score (133.4 [SD 78.5] vs 52.0 [SD 57.5]; p < 0.001) and young age at onset (6.0 [SD 3.0] vs 14.8 [SD 11.8] months; p < 0.001) were each associated with Dravet syndrome vs GEFS+. A combined SCN1A genetic score and seizure onset model separated Dravet syndrome from GEFS+ more effectively (area under the curve [AUC] 0.89 [95% CI 0.86-0.92]) and outperformed all other models (AUC 0.79-0.85; p < 0.001). Model performance was replicated in both validation cohorts 1 (AUC 0.94 [95% CI 0.91-0.97]) and 2 (AUC 0.92 [95% CI 0.82-1.00]). DISCUSSION The prediction model allows objective estimation at disease onset whether a child will develop Dravet syndrome vs GEFS+, assisting clinicians with prognostic counseling and decisions on early institution of precision therapies (http://scn1a-prediction-model.broadinstitute.org/). CLASSIFICATION OF EVIDENCE This study provides Class II evidence that a combined SCN1A genetic score and seizure onset model distinguishes Dravet syndrome from other GEFS+ phenotypes.
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Affiliation(s)
- Andreas Brunklaus
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA.
| | - Eduardo Pérez-Palma
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Ismael Ghanty
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Ji Xinge
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Eva Brilstra
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Berten Ceulemans
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Nicole Chemaly
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Iris de Lange
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Christel Depienne
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Renzo Guerrini
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Davide Mei
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Rikke S Møller
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Rima Nabbout
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Brigid M Regan
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Amy L Schneider
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Ingrid E Scheffer
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - An-Sofie Schoonjans
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Joseph D Symonds
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Sarah Weckhuysen
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Michael W Kattan
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Sameer M Zuberi
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
| | - Dennis Lal
- From the Pediatric Neurosciences Research Group (A.B., I.G., J.D.S., S.M.Z.), Royal Hospital for Children, Glasgow; Institute of Health and Wellbeing (A.B., I.G., J.D.S., S.M.Z.), University of Glasgow, UK; Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana (E.P.-P.), Universidad del Desarrollo, Santiago, Chile; Genomic Medicine Institute, Lerner Research Institute (E.P.-P., D.L.), Department of Quantitative Health Sciences (J.X., M.W.K.), and Epilepsy Center, Neurological Institute (D.L.), Cleveland Clinic, OH; Department of Genetics (E.B., I.d.L.), University Medical Centre, Utrecht, the Netherlands; Department of Child Neurology (B.C., A.-S.S.), University Hospital Antwerp, Belgium; Reference Centre for Rare Epilepsies, Department of Pediatric Neurology (N.C., R.N.), Hôpital Necker-Enfants Malades, Université de Paris, France; Institute of Human Genetics (C.D.), University Hospital Essen, University of Duisburg-Essen, Germany; Neuroscience Department (R.G., D.M.), Children's Hospital A. Meyer-University of Florence, Italy; The Danish Epilepsy Centre (R.S.M.), Dianalund, Denmark; Institute for Regional Health Services (R.S.M.), University of Southern Denmark, Odense; Department of Medicine, Epilepsy Research Centre, Austin Health (B.M.R., A.L.S., I.E.S.), and Florey and Murdoch Children's Research Institutes, Royal Children's Hospital (I.E.S.), University of Melbourne, Australia; Applied and Translational Neurogenomics Group (S.W.), VIB-Center for Molecular Neurology, VIB, Antwerp; Neurology Department (S.W.), University Hospital Antwerp; Institute Born-Bunge (S.W.), University of Antwerp, Belgium; Cologne Center for Genomics (D.L.), University of Cologne, Germany; and Stanley Center for Psychiatric Genetics (D.L.), Broad Institute of MIT and Harvard, Cambridge, MA
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Wang JY, Tang B, Sheng WX, Hua LD, Zeng Y, Fan CX, Deng WY, Gao MM, Zhu WW, He N, Su T. Clinical and Functional Features of Epilepsy-Associated In-Frame Deletion Variants in SCN1A. Front Mol Neurosci 2022; 15:828846. [PMID: 35359575 PMCID: PMC8964123 DOI: 10.3389/fnmol.2022.828846] [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: 12/04/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Objective Naturally occurring in-frame deletion is a unique type of genetic variations, causing the loss of one or more amino acids of proteins. A number of in-frame deletion variants in an epilepsy-associated gene SCN1A, encoding voltage gated sodium channel alpha unit 1.1 (Nav1.1), have been reported in public database. In contrast to the missense and truncation variants, the in-frame deletions in SCN1A remains largely uncharacterized. Methods We summarized the basic information of forty-four SCN1A in-frame deletion variants and performed further analysis on six variants identified in our cases with epilepsy. Mutants of the six in-frame deletions and one truncating variant used as comparison were generated and co-transfected with beta-1 and -2 subunits in tsA201 cells, followed by patch clamp recordings. Results Reviewing all the in-frame deletions showed that they spread over the entire Nav1.1 protein, without obvious “hot spots.” The dominant type (54%) was single residue loss. There was no obvious relationship between the length or locations of deletions and their clinical phenotypes. The six in-frame deletions were two single residue deletions (p.M400del and p.I1772del), one microdeletion (p.S128_F130del) and three macrodeletions (p.T303_R322del, p.T160_Y202del, and p.V1335_V1428del). They scatter and affect different functional domains, including transmembrane helices, pore region, and P-loop. Electrophysiological recordings revealed no measurable sodium current in all of the six mutants. In contrast, the truncating mutant p.M1619Ifs*7 that loses a long stretch of peptides retains partial function. Significance The complete loss-of-function in these shortened, abnormal mutants indicates that Nav1.1 protein is a highly accurate structure, and many of the residues have no redundancy to ion conductance. In-frame deletions caused particularly deleterious effect on protein function possibly due to the disruption of ordered residues.
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Affiliation(s)
- Jing-Yang Wang
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
- Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bin Tang
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Wen-Xiang Sheng
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Li-Dong Hua
- Translational Medicine Center, Maternal and Child Health Research Institute, Guangdong Women and Children’s Hospital, Guangzhou, China
| | - Yang Zeng
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Cui-Xia Fan
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Wei-Yi Deng
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Mei-Mei Gao
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Wei-Wen Zhu
- Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Na He
- Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
- *Correspondence: Tao Su,
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15
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Marco Hernández AV, Tomás Vila M, Caro Llopis A, Monfort S, Martinez F. Case Report: Novel Homozygous Likely Pathogenic SCN1A Variant With Autosomal Recessive Inheritance and Review of the Literature. Front Neurol 2021; 12:784892. [PMID: 34917021 PMCID: PMC8669891 DOI: 10.3389/fneur.2021.784892] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 10/20/2021] [Indexed: 11/17/2022] Open
Abstract
Dominant pathogenic variations in the SCN1A gene are associated with several neuro developmental disorders with or without epilepsy, including Dravet syndrome (DS). Conversely, there are few published cases with homozygous or compound heterozygous variations in the SCN1A gene. Here, we describe two siblings from a consanguineous pedigree with epilepsy phenotype compatible with genetic epilepsy with febrile seizures plus (GEFS+) associated with the homozygous likely pathogenic variant (NM_001165963.1): c.4513A > C (p.Lys1505Gln). Clinical and genetic data were compared to those of other 10 previously published patients with epilepsy and variants in compound heterozygosity or homozygosity in the SCN1A gene. Most patients (11/12) had missense variants. Patients in whom the variants were located at the cytoplasmic or the extracellular domains frequently presented a less severe phenotype than those in whom they are located at the pore-forming domains. Five of the patients (41.7%) meet clinical criteria for Dravet syndrome (DS), one of them associated acute encephalopathy. Other five patients (41.7%) had a phenotype of epilepsy with febrile seizures plus familial origin, while the two remaining (17%) presented focal epileptic seizures. SCN1A-related epilepsies present in most cases an autosomal dominant inheritance; however, there is growing evidence that some genetic variants only manifest clinical symptoms when they are present in both alleles, following an autosomal recessive inheritance.
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Affiliation(s)
- Ana Victoria Marco Hernández
- Neuropediatrics Section, Hospital Universitari i Politècnic La Fe, Valencia, Spain
- Genetics Unit, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | - Miguel Tomás Vila
- Neuropediatrics Section, Hospital Universitari i Politècnic La Fe, Valencia, Spain
| | - Alfonso Caro Llopis
- Genetics Unit, Hospital Universitari i Politècnic La Fe, Valencia, Spain
- Genomics Unit, La Fe Health Research Institute, Valencia, Spain
| | - Sandra Monfort
- Genomics Unit, La Fe Health Research Institute, Valencia, Spain
| | - Francisco Martinez
- Genetics Unit, Hospital Universitari i Politècnic La Fe, Valencia, Spain
- Genomics Unit, La Fe Health Research Institute, Valencia, Spain
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16
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Gorman KM, Peters CH, Lynch B, Jones L, Bassett DS, King MD, Ruben PC, Rosch RE. Persistent sodium currents in SCN1A developmental and degenerative epileptic dyskinetic encephalopathy. Brain Commun 2021; 3:fcab235. [PMID: 34755109 PMCID: PMC8568850 DOI: 10.1093/braincomms/fcab235] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/15/2021] [Accepted: 06/21/2021] [Indexed: 11/14/2022] Open
Abstract
Pathogenic variants in the voltage-gated sodium channel gene (SCN1A) are amongst the most common genetic causes of childhood epilepsies. There is considerable heterogeneity in both the types of causative variants and associated phenotypes; a recent expansion of the phenotypic spectrum of SCN1A associated epilepsies now includes an early onset severe developmental and epileptic encephalopathy with regression and a hyperkinetic movement disorder. Herein, we report a female with a developmental and degenerative epileptic-dyskinetic encephalopathy, distinct and more severe than classic Dravet syndrome. Clinical diagnostics indicated a paternally inherited c.5053G>T; p. A1685S variant of uncertain significance in SCN1A. Whole-exome sequencing detected a second de novo mosaic (18%) c.2345G>A; p. T782I likely pathogenic variant in SCN1A (maternal allele). Biophysical characterization of both mutant channels in a heterologous expression system identified gain-of-function effects in both, with a milder shift in fast inactivation of the p. A1685S channels; and a more severe persistent sodium current in the p. T782I. Using computational models, we show that large persistent sodium currents induce hyper-excitability in individual cortical neurons, thus relating the severe phenotype to the empirically quantified sodium channel dysfunction. These findings further broaden the phenotypic spectrum of SCN1A associated epilepsies and highlight the importance of testing for mosaicism in epileptic encephalopathies. Detailed biophysical evaluation and computational modelling further highlight the role of gain-of-function variants in the pathophysiology of the most severe phenotypes associated with SCN1A.
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Affiliation(s)
- Kathleen M Gorman
- Department of Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Colin H Peters
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada.,Department of Physiology and Biophysics, University of Colorado, Denver, CO, USA
| | - Bryan Lynch
- Department of Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland
| | - Laura Jones
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
| | - Dani S Bassett
- Departments of Bioengineering, Electrical & Systems Engineering, Physics & Astronomy, Neurology, and Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.,Santa Fe Institute, Santa Fe, NM, USA
| | - Mary D King
- Department of Neurology and Clinical Neurophysiology, Children's Health Ireland at Temple Street, Dublin, Ireland.,School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada
| | - Richard E Rosch
- Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.,MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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17
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Li W, Schneider AL, Scheffer IE. Defining Dravet syndrome: An essential pre-requisite for precision medicine trials. Epilepsia 2021; 62:2205-2217. [PMID: 34338318 PMCID: PMC9291974 DOI: 10.1111/epi.17015] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/21/2021] [Accepted: 07/12/2021] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The classical description of Dravet syndrome, the prototypic developmental and epileptic encephalopathy, is of a normal 6-month-old infant presenting with a prolonged, febrile, hemiclonic seizure and showing developmental slowing after age 1 year. SCN1A pathogenic variants are found in >80% of patients. Many patients have atypical features resulting in diagnostic delay and inappropriate therapy. We aimed to provide an evidence-based definition of SCN1A-Dravet syndrome in readiness for precision medicine trials. METHODS Epilepsy patients were recruited to the University of Melbourne Epilepsy Genetics Research Program between 1995 and 2020 by neurologists from around the world. Patients with SCN1A pathogenic variants were reviewed and only those with Dravet syndrome were included. Clinical data, including seizure and developmental course, were analyzed in all patients with SCN1A-Dravet syndrome. RESULTS Two hundred and five patients were studied at a median age of 8.5 years (range 10 months to 60 years); 25 were deceased. The median seizure-onset age was 5.7 months (range 1.5-20.6 months). Initial seizures were tonic-clonic (52%) and hemiclonic (35%), with only 55% being associated with fever. Only 34% of patients presented with status epilepticus (seizure lasting ≥30 minutes). Median time between first and second seizure was 30 days (range 4 hours to 8 months), and seven patients (5%) had at least 6 months between initial seizures. Median ages at onset of second and third seizure types were 9.1 months (range 3 months-25.4 years) and 15.5 months (range 4 months-8.2 years), respectively. Developmental slowing occurred prior to 12 months in 27%. SIGNIFICANCE An evidence-based definition of SCN1A-Dravet syndrome is essential for early diagnosis. We refine the spectrum of Dravet syndrome, based on patterns of seizure onset, type, and progression. Understanding of the full spectrum of SCN1A-Dravet syndrome presentation is essential for early diagnosis and optimization of treatment, especially as precision medicine trials become available.
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Affiliation(s)
- Wenhui Li
- Children's Hospital of Fudan University, Shanghai, China.,Department of Medicine, Austin Health, Epilepsy Research Centre, University of Melbourne, Heidelberg, Vic., Australia
| | - Amy L Schneider
- Department of Medicine, Austin Health, Epilepsy Research Centre, University of Melbourne, Heidelberg, Vic., Australia
| | - Ingrid E Scheffer
- Department of Medicine, Austin Health, Epilepsy Research Centre, University of Melbourne, Heidelberg, Vic., Australia.,Florey Institute of Neuroscience and Mental Health, Heidelberg, Vic., Australia.,Murdoch Children's Research Institute and Department of Paediatrics, Royal Children's Hospital, University of Melbourne, Parkville, Vic., Australia
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18
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Khoshkhoo S, Lal D, Walsh CA. Application of single cell genomics to focal epilepsies: A call to action. Brain Pathol 2021; 31:e12958. [PMID: 34196990 PMCID: PMC8412079 DOI: 10.1111/bpa.12958] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 12/24/2022] Open
Abstract
Focal epilepsies are the largest epilepsy subtype and associated with significant morbidity. Somatic variation is a newly recognized genetic mechanism underlying a subset of focal epilepsies, but little is known about the processes through which somatic mosaicism causes seizures, the cell types carrying the pathogenic variants, or their developmental origin. Meanwhile, the inception of single cell biology has completely revolutionized the study of neurological diseases and has the potential to answer some of these key questions. Focusing on single cell genomics, transcriptomics, and epigenomics in focal epilepsy research, circumvents the averaging artifact associated with studying bulk brain tissue and offers the kind of granularity that is needed for investigating the consequences of somatic mosaicism. Here we have provided a brief overview of some of the most developed single cell techniques and the major considerations around applying them to focal epilepsy research.
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Affiliation(s)
- Sattar Khoshkhoo
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Dennis Lal
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.,Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Christopher A Walsh
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, USA.,Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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19
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Sub-genic intolerance, ClinVar, and the epilepsies: A whole-exome sequencing study of 29,165 individuals. Am J Hum Genet 2021; 108:965-982. [PMID: 33932343 DOI: 10.1016/j.ajhg.2021.04.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/08/2021] [Indexed: 12/23/2022] Open
Abstract
Both mild and severe epilepsies are influenced by variants in the same genes, yet an explanation for the resulting phenotypic variation is unknown. As part of the ongoing Epi25 Collaboration, we performed a whole-exome sequencing analysis of 13,487 epilepsy-affected individuals and 15,678 control individuals. While prior Epi25 studies focused on gene-based collapsing analyses, we asked how the pattern of variation within genes differs by epilepsy type. Specifically, we compared the genetic architectures of severe developmental and epileptic encephalopathies (DEEs) and two generally less severe epilepsies, genetic generalized epilepsy and non-acquired focal epilepsy (NAFE). Our gene-based rare variant collapsing analysis used geographic ancestry-based clustering that included broader ancestries than previously possible and revealed novel associations. Using the missense intolerance ratio (MTR), we found that variants in DEE-affected individuals are in significantly more intolerant genic sub-regions than those in NAFE-affected individuals. Only previously reported pathogenic variants absent in available genomic datasets showed a significant burden in epilepsy-affected individuals compared with control individuals, and the ultra-rare pathogenic variants associated with DEE were located in more intolerant genic sub-regions than variants associated with non-DEE epilepsies. MTR filtering improved the yield of ultra-rare pathogenic variants in affected individuals compared with control individuals. Finally, analysis of variants in genes without a disease association revealed a significant burden of loss-of-function variants in the genes most intolerant to such variation, indicating additional epilepsy-risk genes yet to be discovered. Taken together, our study suggests that genic and sub-genic intolerance are critical characteristics for interpreting the effects of variation in genes that influence epilepsy.
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20
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Rampazzo ACM, Dos Santos RRP, Maluf FA, Simm RF, Marson FAL, Ortega MM, de Aguiar PHP. Dravet syndrome and Dravet syndrome-like phenotype: a systematic review of the SCN1A and PCDH19 variants. Neurogenetics 2021; 22:105-115. [PMID: 33937968 DOI: 10.1007/s10048-021-00644-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
Dravet syndrome (DS) is a rare and severe epileptic syndrome of childhood with prevalence between 1/22,000 and 1/49,900 of live births. Approximately 80% of patients with this syndrome present SCN1A pathogenic variants, which encodes an alpha subunit of a neural voltage-dependent sodium channel. There is a correlation between PCDH19 pathogenic variants, encodes the protocadherin 19, and a similar disease to DS known as DS-like phenotype. The present review aims to clarify the differences between DS and DS-like phenotype according to the SCN1A and PCDH19 variants. A systematic review was conducted in PubMed and Virtual Health Library (VHL) databases, using "Dravet Syndrome" and "Severe Myoclonic Epilepsy in Infancy (SMEI)" search words, selecting cohort of studies published in journal with impact factor of two or greater. The systematic review was according to the Preferred Reporting Items for Systematic Review and Meta-Analysis recommendations. Nineteen studies were included in the present review, and a significant proportion of patients with DS-carrying SCN1A was greater than patients with DS-like phenotype-harboring PCDH19 variants (76.6% versus 23.4%). When clinical and genetic data were correlated, autism was predominantly observed in patients with DS-like-carrying PCDH19 variants compared to SCN1A variant carriers (62.5% versus 37.5%, respectively, P-value = 0.044, P-value corrected = 0.198). In addition, it was noticed a significant predisposition to hyperthermia during epilepsy crisis in individuals carrying PCDH19 variants (P-value = 0.003; P-value corrected = 0.027). The present review is the first to point out differences between the DS and DS-like phenotype according to the SCN1A and PCDH19 variants.
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Affiliation(s)
- Ana Carla Mondek Rampazzo
- Pontifical Catholic University of Paraná, 485 Jockei Club Ave., Londrina, Paraná, 86072-360, Brazil.
| | | | - Fernando Arfux Maluf
- Pontifical Catholic University of Paraná, 485 Jockei Club Ave., Londrina, Paraná, 86072-360, Brazil
| | - Renata Faria Simm
- Neurophysiology Clinic, Clinics Hospital, São Paulo, São Paulo, Brazil
| | - Fernando Augusto Lima Marson
- Laboratory of Cellular and Molecular Biology of Tumors and Bioactive Compounds and Laboratory of Human and Medical Genetics, São Francisco University, Bragança Paulista, São Paulo, Brazil
| | - Manoela Marques Ortega
- Laboratory of Cellular and Molecular Biology of Tumors and Bioactive Compounds and Laboratory of Human and Medical Genetics, São Francisco University, Bragança Paulista, São Paulo, Brazil
| | - Paulo Henrique Pires de Aguiar
- Laboratory of Cellular and Molecular Biology of Tumors and Bioactive Compounds and Laboratory of Human and Medical Genetics, São Francisco University, Bragança Paulista, São Paulo, Brazil
- Department of Neurosurgery, Postgraduate Program in Health Sciences, State Public Medical Assistance Institute, Department of Neurosurgery, Santa Paula Hospital, São Paulo, São Paulo, Brazil
- Research and Innovation Department of the Cellular and Molecular Biology Laboratory of the ABC, School of Medicine, Santo André, São Paulo, São Paulo, Brazil
- Department of Neurology, School of Medicine, Pontifical Catholic University of São Paulo, São Paulo, Brazil
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21
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Alonso-Gonzalez A, Calaza M, Amigo J, González-Peñas J, Martínez-Regueiro R, Fernández-Prieto M, Parellada M, Arango C, Rodriguez-Fontenla C, Carracedo A. Exploring the biological role of postzygotic and germinal de novo mutations in ASD. Sci Rep 2021; 11:319. [PMID: 33431980 PMCID: PMC7801448 DOI: 10.1038/s41598-020-79412-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 11/30/2020] [Indexed: 12/11/2022] Open
Abstract
De novo mutations (DNMs), including germinal and postzygotic mutations (PZMs), are a strong source of causality for Autism Spectrum Disorder (ASD). However, the biological processes involved behind them remain unexplored. Our aim was to detect DNMs (germinal and PZMs) in a Spanish ASD cohort (360 trios) and to explore their role across different biological hierarchies (gene, biological pathway, cell and brain areas) using bioinformatic approaches. For the majority of the analysis, a combined ASD cohort (N = 2171 trios) was created using previously published data by the Autism Sequencing Consortium (ASC). New plausible candidate genes for ASD such as FMR1 and NFIA were found. In addition, genes harboring PZMs were significantly enriched for miR-137 targets in comparison with germinal DNMs that were enriched in GO terms related to synaptic transmission. The expression pattern of genes with PZMs was restricted to early mid-fetal cortex. In contrast, the analysis of genes with germinal DNMs revealed a spatio-temporal window from early to mid-fetal development stages, with expression in the amygdala, cerebellum, cortex and striatum. These results provide evidence of the pathogenic role of PZMs and suggest the existence of distinct mechanisms between PZMs and germinal DNMs that are influencing ASD risk.
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Affiliation(s)
- A Alonso-Gonzalez
- Grupo de Medicina Xenómica, Fundación Instituto de Investigación Sanitaria de Santiago de Compostela (FIDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Genomics and Bioinformatics Group, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Av Barcelona 31, 15706, Santiago de Compostela, Spain
| | - M Calaza
- Grupo de Medicina Xenómica, Fundación Instituto de Investigación Sanitaria de Santiago de Compostela (FIDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Genomics and Bioinformatics Group, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Av Barcelona 31, 15706, Santiago de Compostela, Spain
| | - J Amigo
- Fundación Pública Galega de Medicina Xenómica (FPGMX), Centro de Investigación Biomédica en Red, Enfermedades Raras (CIBERER), Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - J González-Peñas
- Centro De Investigación Biomédica en Red de Salud Mental (CIBERSAM), Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, School of Medicine, Universidad Complutense, Madrid, Spain
| | - R Martínez-Regueiro
- Grupo de Medicina Xenómica, Fundación Instituto de Investigación Sanitaria de Santiago de Compostela (FIDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Genomics and Bioinformatics Group, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Av Barcelona 31, 15706, Santiago de Compostela, Spain
| | - M Fernández-Prieto
- Grupo de Medicina Xenómica, Fundación Instituto de Investigación Sanitaria de Santiago de Compostela (FIDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Genomics and Bioinformatics Group, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Av Barcelona 31, 15706, Santiago de Compostela, Spain
| | - M Parellada
- Centro De Investigación Biomédica en Red de Salud Mental (CIBERSAM), Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, School of Medicine, Universidad Complutense, Madrid, Spain
| | - C Arango
- Centro De Investigación Biomédica en Red de Salud Mental (CIBERSAM), Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, IiSGM, School of Medicine, Universidad Complutense, Madrid, Spain
| | - Cristina Rodriguez-Fontenla
- Genomics and Bioinformatics Group, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Av Barcelona 31, 15706, Santiago de Compostela, Spain.
| | - A Carracedo
- Grupo de Medicina Xenómica, Fundación Instituto de Investigación Sanitaria de Santiago de Compostela (FIDIS), Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Genomics and Bioinformatics Group, Center for Research in Molecular Medicine and Chronic Diseases (CiMUS), Universidade de Santiago de Compostela, Av Barcelona 31, 15706, Santiago de Compostela, Spain.,Fundación Pública Galega de Medicina Xenómica (FPGMX), Centro de Investigación Biomédica en Red, Enfermedades Raras (CIBERER), Universidad de Santiago de Compostela, Santiago de Compostela, Spain
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22
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Salinas V, Vega P, Marsili L, Pérez‐Maturo J, Martínez N, Zavala L, González‐Morón D, Medina N, Rodriguez‐Quiroga SA, Amartino H, Maxit C, Sturchio A, Grimberg B, Duque K, Comas B, Silva W, Consalvo D, Sfaello I, Espay AJ, Kauffman MA. The odyssey of complex neurogenetic disorders: From undetermined to positive. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:876-884. [DOI: 10.1002/ajmg.c.31848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/14/2020] [Accepted: 09/27/2020] [Indexed: 12/22/2022]
Affiliation(s)
- Valeria Salinas
- Neurogenetics Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
- Faculty of Biomedical Sciences, Precision Medicine and Clinical Genomics Group, Translational Medicine Research Institute‐CONICET Universidad Austral Buenos Aires Argentina
| | - Patricia Vega
- Neurogenetics Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
| | - Luca Marsili
- UC Gardner Neuroscience Institute, Department of Neurology, Gardner Center for Parkinson's disease and Movement Disorders University of Cincinnati Ohio
| | - Josefina Pérez‐Maturo
- Neurogenetics Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
- Faculty of Biomedical Sciences, Precision Medicine and Clinical Genomics Group, Translational Medicine Research Institute‐CONICET Universidad Austral Buenos Aires Argentina
| | - Nerina Martínez
- Neurogenetics Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
| | - Lucia Zavala
- Neurogenetics Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
| | | | - Nancy Medina
- Neurogenetics Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
| | | | - Hernán Amartino
- Pediatric Neurology Unit Hospital Universitario Austral Buenos Aires Argentina
| | - Clarisa Maxit
- Pediatric Neurology Unit, Hospital Italiano de Buenos Aires Buenos Aires Argentina
| | - Andrea Sturchio
- UC Gardner Neuroscience Institute, Department of Neurology, Gardner Center for Parkinson's disease and Movement Disorders University of Cincinnati Ohio
| | - Barbara Grimberg
- UC Gardner Neuroscience Institute, Department of Neurology, Gardner Center for Parkinson's disease and Movement Disorders University of Cincinnati Ohio
| | - Kevin Duque
- UC Gardner Neuroscience Institute, Department of Neurology, Gardner Center for Parkinson's disease and Movement Disorders University of Cincinnati Ohio
| | - Betiana Comas
- Neurology Unit, Hospital de la Baxada “Dra. Teresa Ratto” Paraná Entre Ríos Argentina
| | - Walter Silva
- Pediatric Neurology Unit, Hospital Italiano de Buenos Aires Buenos Aires Argentina
| | - Damián Consalvo
- Neurology Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
| | - Ignacio Sfaello
- CETES, Instituto de Neurología Infanto‐Juvenil Córdoba Argentina
| | - Alberto J. Espay
- UC Gardner Neuroscience Institute, Department of Neurology, Gardner Center for Parkinson's disease and Movement Disorders University of Cincinnati Ohio
| | - Marcelo A. Kauffman
- Neurogenetics Unit, Hospital JM Ramos Mejía Buenos Aires Argentina
- Faculty of Biomedical Sciences, Precision Medicine and Clinical Genomics Group, Translational Medicine Research Institute‐CONICET Universidad Austral Buenos Aires Argentina
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Ohmori I, Kobayashi K, Ouchida M. Scn1a and Cacna1a mutations mutually alter their original phenotypes in rats. Neurochem Int 2020; 141:104859. [PMID: 33045260 DOI: 10.1016/j.neuint.2020.104859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/31/2020] [Accepted: 09/26/2020] [Indexed: 12/20/2022]
Abstract
This study aimed to examine the effects of Cacna1a mutation on the phenotype of Scn1a-associated epilepsy in rats. We used rats with an N1417H missense mutation in the Scn1a gene and others with an M251K mutation in the Cacna1a gene. Scn1a/Cacna1a double mutant rats were generated by mating both Scn1a and Cacna1a mutants. We investigated general health and the epileptic phenotype in all these genotypes. The onset threshold of hyperthermia-induced seizures was examined at 5 weeks and spontaneous seizures were monitored using video-EEG recordings from 6 to 12 weeks of age. Scn1a/Cacna1a double mutants showed significantly reduced threshold for hyperthermia-sensitive seizures onset compared with the Scn1a mutants and had absence seizures having 6-7 c/s spike-wave bursts with changes in the spike-wave pattern, whereas Cacna1a mutants had regular 6-7 c/s spike-wave bursts. In Scn1a/Cacna1a double mutants, 6-7 c/s spike-wave bursts were accompanied with eyelid myoclonia and continuously shifting generalized clonic seizures, which were not observed in either Scn1a or Cacna1a mutants. Although a curvature of the spine was observed in rats of all these genotypes, the degree of curvature was more pronounced in Scn1a/Cacna1a double mutants, followed by Cacna1a and Scn1a mutants. Our results indicate that Cacna1a and Scn1a mutations mutually alter their original phenotypes in rats. The phenotype of absence seizures with eyelid myoclonia, generalized clonic seizures, and of spine curvature in the Scn1a/Cacna1a double mutants were similar to that observed in patients with Dravet syndrome.
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Affiliation(s)
- Iori Ohmori
- Graduate School of Education, Okayama University, Tsushima 3-chome 1-1, Kita-ku, Okayama, 700-8530, Japan; Department of Child Neurology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Shikatacho 2-chome 5-1, Kita-ku, Okayama, 700-8558, Japan; Department of Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Shikatacho 2-chome 5-1, Kita-ku, Okayama, 700-8558, Japan.
| | - Kiyoka Kobayashi
- Department of Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Shikatacho 2-chome 5-1, Kita-ku, Okayama, 700-8558, Japan
| | - Mamoru Ouchida
- Department of Molecular Oncology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Shikatacho 2-chome 5-1, Kita-ku, Okayama, 700-8558, Japan
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24
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MosaicBase: A Knowledgebase of Postzygotic Mosaic Variants in Noncancer Disease-related and Healthy Human Individuals. GENOMICS PROTEOMICS & BIOINFORMATICS 2020; 18:140-149. [PMID: 32911083 PMCID: PMC7646124 DOI: 10.1016/j.gpb.2020.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 03/18/2020] [Accepted: 05/31/2020] [Indexed: 12/14/2022]
Abstract
Mosaic variants resulting from postzygotic mutations are prevalent in the human genome and play important roles in human diseases. However, except for cancer-related variants, there is no collection of postzygotic mosaic variants in noncancer disease-related and healthy individuals. Here, we present MosaicBase, a comprehensive database that includes 6698 mosaic variants related to 266 noncancer diseases and 27,991 mosaic variants identified in 422 healthy individuals. Genomic and phenotypic information of each variant was manually extracted and curated from 383 publications. MosaicBase supports the query of variants with Online Mendelian Inheritance in Man (OMIM) entries, genomic coordinates, gene symbols, or Entrez IDs. We also provide an integrated genome browser for users to easily access mosaic variants and their related annotations for any genomic region. By analyzing the variants collected in MosaicBase, we find that mosaic variants that directly contribute to disease phenotype show features distinct from those of variants in individuals with mild or no phenotypes, in terms of their genomic distribution, mutation signatures, and fraction of mutant cells. MosaicBase will not only assist clinicians in genetic counseling and diagnosis but also provide a useful resource to understand the genomic baseline of postzygotic mutations in the general human population. MosaicBase is publicly available at http://mosaicbase.com/ or http://49.4.21.8:8000.
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25
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Mei D, Cetica V, Marini C, Guerrini R. Dravet syndrome as part of the clinical and genetic spectrum of sodium channel epilepsies and encephalopathies. Epilepsia 2020; 60 Suppl 3:S2-S7. [PMID: 31904125 DOI: 10.1111/epi.16054] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 01/01/2023]
Abstract
Dravet syndrome is the most studied form of genetic epilepsy. It has now been clarified that the clinical spectrum of the syndrome does not have firmly established boundaries. The core phenotype is characterized by intractable, mainly clonic, seizures precipitated by increased body temperature with onset in the first year of life and subsequent appearance of multiple seizures types still precipitated by, but not confined to, hyperthermia. Cognitive impairment is invariably present when the full syndrome is manifested. This complex of symptoms is related to mutations in the SCN1A gene, which are often de novo and constitutional but can also be inherited from a parent with less severe clinical manifestations or be present as somatic mosaicism. Inheritance from less severely affected individuals, at times only having experienced a few febrile seizures, and differences in severity, even within the same family, with a subset of patients only showing fragments of the syndrome, testify to a remarkable phenotypic heterogeneity as far as severity, but less so clinical phenomenology, are concerned. This characteristic, together with underascertainment of SCN1A mutations due to human errors or technical limitations in uncovering alternative pathogenic molecular mechanisms, such as genomic rearrangements or poison exons, has contributed to making clinicians and geneticists suspicious that Dravet syndrome may be caused by more than one gene. This opinion has been further amplified by the description of other genetic disorders, such as PCDH19- or CHD2-related epilepsy, whose phenotypes have included fragments of the Dravet phenotypic spectrum, and by the suboptimal characterization of phenotypes associated with mutations in SCN1B, HCN1, KCN2A, GABRA1, GABRG2, and STXBP1. The SCN1A gene-Dravet syndrome association is in our opinion highly specific. However, because the syndrome spectrum is wide, fragments of it can at times also be manifested in other genetic epilepsy syndromes, thereby leading to overdiagnosis of Dravet syndrome beyond SCN1A. Dravet syndrome is in turn a severe SCN1A phenotype within a continuum of SCN1A-related clinical phenomenology.
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Affiliation(s)
- Davide Mei
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital-University of Florence, Florence, Italy
| | - Valentina Cetica
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital-University of Florence, Florence, Italy
| | - Carla Marini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital-University of Florence, Florence, Italy
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital-University of Florence, Florence, Italy.,IRCCS Stella Maris Foundation, Pisa, Italy
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26
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Shmuely S, Surges R, Helling RM, Gunning WB, Brilstra EH, Verhoeven JS, Cross JH, Sisodiya SM, Tan HL, Sander JW, Thijs RD. Cardiac arrhythmias in Dravet syndrome: an observational multicenter study. Ann Clin Transl Neurol 2020; 7:462-473. [PMID: 32207228 PMCID: PMC7187713 DOI: 10.1002/acn3.51017] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 02/25/2020] [Indexed: 11/11/2022] Open
Abstract
Objectives We ascertained the prevalence of ictal arrhythmias to explain the high rate of sudden unexpected death in epilepsy (SUDEP) in Dravet syndrome (DS). Methods We selected cases with clinical DS, ≥6 years, SCN1A mutation, and ≥1 seizure/week. Home‐based ECG recordings were performed for 20 days continuously. Cases were matched for age and sex to two epilepsy controls with no DS and ≥1 major motor seizure during video‐EEG. We determined the prevalence of peri‐ictal asystole, bradycardia, QTc changes, and effects of convulsive seizures (CS) on heart rate, heart rate variability (HRV), and PR/QRS. Generalized estimating equations were used to account for multiple seizures within subjects, seizure type, and sleep/wakefulness. Results We included 59 cases. Ictal recordings were obtained in 45 cases and compared to 90 controls. We analyzed 547 seizures in DS (300 CS) and 169 in controls (120 CS). No asystole occurred. Postictal bradycardia was more common in controls (n = 11, 6.5%) than cases (n = 4, 0.7%; P = 0.002). Peri‐ictal QTc‐lengthening (≥60ms) occurred more frequently in DS (n = 64, 12%) than controls (n = 8, 4.7%, P = 0.048); pathologically prolonged QTc was rare (once in each group). In DS, interictal HRV was lower compared to controls (RMSSD P = 0.029); peri‐ictal values did not differ between the groups. Prolonged QRS/PR was rare and more common in controls (QRS: one vs. none; PR: three vs. one). Interpretation We did not identify major arrhythmias in DS which can directly explain high SUDEP rates. Peri‐ictal QTc‐lengthening was, however, more common in DS. This may reflect unstable repolarization and an increased propensity for arrhythmias.
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Affiliation(s)
- Sharon Shmuely
- Stichting Epilepsie Instellingen Nederland - SEIN, Achterweg 5, 2103 SW Heemstede, Dokter Denekampweg 20, 8025 BV, Zwolle, The Netherlands.,NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Bonn, Germany.,Centre for Rare Diseases Bonn (ZSEB), University Hospital Bonn, Bonn, Germany
| | - Robert M Helling
- Stichting Epilepsie Instellingen Nederland - SEIN, Achterweg 5, 2103 SW Heemstede, Dokter Denekampweg 20, 8025 BV, Zwolle, The Netherlands
| | - W Boudewijn Gunning
- Stichting Epilepsie Instellingen Nederland - SEIN, Achterweg 5, 2103 SW Heemstede, Dokter Denekampweg 20, 8025 BV, Zwolle, The Netherlands
| | - Eva H Brilstra
- Department of Medical Genetics, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Judith S Verhoeven
- Academic Centre for Epileptology Kempenhaeghe, 5590AB Heeze, Heeze, The Netherlands
| | - J Helen Cross
- UCL NIHR BRC Great Ormond Street Institute of Child Health (ICH), 30 Guilford St, London, WC1N 1EH, UK
| | - Sanjay M Sisodiya
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK.,Chalfont Centre for Epilepsy, Bucks, SL9 0RJ, UK
| | - Hanno L Tan
- Heart Centre, Department of Experimental and Clinical Cardiology, Amsterdam University Medical Centres, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.,Netherlands Heart Institute, Moreelsepark 1, 3511 EP, Utrecht, The Netherlands
| | - Josemir W Sander
- Stichting Epilepsie Instellingen Nederland - SEIN, Achterweg 5, 2103 SW Heemstede, Dokter Denekampweg 20, 8025 BV, Zwolle, The Netherlands.,NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK.,Chalfont Centre for Epilepsy, Bucks, SL9 0RJ, UK
| | - Roland D Thijs
- Stichting Epilepsie Instellingen Nederland - SEIN, Achterweg 5, 2103 SW Heemstede, Dokter Denekampweg 20, 8025 BV, Zwolle, The Netherlands.,NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK.,Department of Neurology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
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27
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de Lange IM, Mulder F, van 't Slot R, Sonsma ACM, van Kempen MJA, Nijman IJ, Ernst RF, Knoers NVAM, Brilstra EH, Koeleman BPC. Modifier genes in SCN1A-related epilepsy syndromes. Mol Genet Genomic Med 2020; 8:e1103. [PMID: 32032478 PMCID: PMC7196470 DOI: 10.1002/mgg3.1103] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/24/2022] Open
Abstract
Background SCN1A is one of the most important epilepsy‐related genes, with pathogenic variants leading to a range of phenotypes with varying disease severity. Different modifying factors have been hypothesized to influence SCN1A‐related phenotypes. We investigate the presence of rare and more common variants in epilepsy‐related genes as potential modifiers of SCN1A‐related disease severity. Methods 87 patients with SCN1A‐related epilepsy were investigated. Whole‐exome sequencing was performed by the Beijing Genomics Institute (BGI). Functional variants in 422 genes associated with epilepsy and/or neuronal excitability were investigated. Differences in proportions of variants between the epilepsy genes and four control gene sets were calculated, and compared to the proportions of variants in the same genes in the ExAC database. Results Statistically significant excesses of variants in epilepsy genes were observed in the complete cohort and in the combined group of mildly and severely affected patients, particularly for variants with minor allele frequencies of <0.05. Patients with extreme phenotypes showed much greater excesses of epilepsy gene variants than patients with intermediate phenotypes. Conclusion Our results indicate that relatively common variants in epilepsy genes, which would not necessarily be classified as pathogenic, may play a large role in modulating SCN1A phenotypes. They may modify the phenotypes of both severely and mildly affected patients. Our results may be a first step toward meaningful testing of modifier gene variants in regular diagnostics for individual patients, to provide a better estimation of disease severity for newly diagnosed patients.
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Affiliation(s)
- Iris M de Lange
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Flip Mulder
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ruben van 't Slot
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Anja C M Sonsma
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marjan J A van Kempen
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Isaac J Nijman
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Robert F Ernst
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Nine V A M Knoers
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Genetics, University Medical Center Groningen, Groningen, The Netherlands
| | - Eva H Brilstra
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bobby P C Koeleman
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
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28
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Abstract
SCN1A gene mutations are associated with epilepsy and neurodevelopmental disorders. This study aimed to explore the genotype and phenotype spectrum of SCN1A gene related epilepsy. Epileptic patients who were treated in the Children's Hospital of Chongqing Medical University from January 2015 to July 2018 and identified as having SCN1A mutations by targeted next-generation sequencing were included. Clinical manifestations of all patients were analyzed retrospectively. A total of 24 patients with SCN1A mutations were identified. The age of epilepsy onset ranged from 2 months to 2 years and 9 months. Multiple seizure types were observed. A total of 13 (54.2%) patients had three or more types of seizures. Overall, 16 (66.7%) patients had status epilepticus, 11 (45.8%) patients had fever sensitivity, and nine (37.5%) patients had seizures after vaccination. Moreover, 15 (62.5%) patients showed varying degrees of cognitive and motor development retardation. In addition, two patients had mutations inherited from one of their parents and 22 (91.7%) patients had de novo mutations. The following SCN1A mutation types were identified: missense (16 patients, 66.7%), nonsense (four patients, 16.7%), splice site (one patient), frameshift (one patient), and large deletions (two patients). Overall, 23 of the patients received antiepileptic therapy, of which eight (33.3%) patients had no decrease in seizures and 11 (45.8%) patients had more than 50% decrease in seizure frequency. Three patients had poor response to antiepileptic drug therapy before attempting ketogenic diet, after which seizure frequency decreased by 50%. A total of 10 (41.7%) patients had used sodium channel blockers before accurate diagnosis, all of whom showed ineffective or even aggravated seizure response. SCN1A mutations are associated with a spectrum of seizure-related disorders, ranging from a relatively mild form of febrile seizures to a more severe epileptic encephalopathy known as Dravet syndrome. Early diagnosis of SCN1A mutation-associated epilepsy can aid in appropriate choice of antiepileptic drugs for treatment and reducing adverse sequelae.
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29
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What is the role of next generation sequencing in status epilepticus? Epilepsy Behav 2019; 101:106373. [PMID: 31300382 DOI: 10.1016/j.yebeh.2019.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 06/11/2019] [Indexed: 02/01/2023]
Abstract
Status epilepticus is a life-threatening medical condition which requires immediate diagnosis and treatment. In children, it may be a recurrent manifestation in the context of heterogeneous severe developmental genetic encephalopathies, as well as the first neurological manifestation. Mutations in several genes have been consistently associated with status epilepticus despite none of them can be considered as 'pure' Mendelian status epilepticus gene. Most genetic conditions featuring status epilepticus can be assigned to specific phenotypic subgroups, including cortical dysplasias, inborn errors of metabolism, mitochondrial diseases, or epileptic encephalopathies and childhood syndromes. Next generation sequencing (NGS) has increased the number of genes associated with, and improved the turnaround time for molecular diagnosis of, status epilepticus, allowing more timely and rationale management choices for specific conditions. Next generation sequencing might become part of the standard of care in the near future for a large subset of patients with status epilepticus, especially in early life. At present, trios whole exome sequencing, with a first analysis of point and copy number variants of an in silico panel containing 'status epilepticus' genes might represent best choice as it would allow a rapid screening. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
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30
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Till Á, Zima J, Fekete A, Bene J, Czakó M, Szabó A, Melegh B, Hadzsiev K. Mutation spectrum of the SCN1A gene in a Hungarian population with epilepsy. Seizure 2019; 74:8-13. [PMID: 31765958 DOI: 10.1016/j.seizure.2019.10.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/30/2019] [Accepted: 10/29/2019] [Indexed: 01/05/2023] Open
Abstract
PURPOSE The vast majority of mutations responsible for epilepsy syndromes such as genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS) occur in the gene encoding the type 1 alpha subunit of neuronal voltage-gated sodium channel (SCN1A). METHODS 63 individuals presenting with either DS or GEFS + syndrome phenotype were screened for SCN1A gene mutation using Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). RESULTS Our research study identified 15 novel pathogen mutations in the SCN1A gene of which 12 appeared to be missense mutations with addition of two frameshift-deletions and one in-frame deletion. The distribution of clinical phenotypes in patients carrying SCN1A mutations was as follows: twelve patients had classical DS, three patients had GEFS + syndrome and two relatives of DS patients were suffering from febrile seizures. CONCLUSIONS Our study highlights the phenotypic and genotypic heterogeneities of DS and GEFS + with the important aim of gaining a deeper understanding of SCN1A-related disorders. This study also represents the first genetic analysis of the SCN1A gene in a Hungarian cohort with the DS and GEFS + syndrome phenotype.
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Affiliation(s)
- Ágnes Till
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| | - Judith Zima
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| | - Anett Fekete
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary
| | - Judit Bene
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary; Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Márta Czakó
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary; Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - András Szabó
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary; Szentágothai Research Center, University of Pécs, Pécs, Hungary
| | - Béla Melegh
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary; Szentágothai Research Center, University of Pécs, Pécs, Hungary.
| | - Kinga Hadzsiev
- Department of Medical Genetics, Medical School, Clinical Center, University of Pécs, Pécs, Hungary; Szentágothai Research Center, University of Pécs, Pécs, Hungary
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31
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Ellis CA, Petrovski S, Berkovic SF. Epilepsy genetics: clinical impacts and biological insights. Lancet Neurol 2019; 19:93-100. [PMID: 31494011 DOI: 10.1016/s1474-4422(19)30269-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 05/18/2019] [Accepted: 06/11/2019] [Indexed: 01/23/2023]
Abstract
Genomics now has an increasingly important role in neurology clinics. Regarding the epilepsies, innovations centred around technology, analytics, and collaboration have led to remarkable progress in gene discovery and have revealed the diverse array of genetic mechanisms and neurobiological pathways that contribute to these disorders. The new genomic era can present a challenge to clinicians, who now find themselves asked to interpret and apply genetic data to their daily management of patients with epilepsy. Navigation of this new era will require genetic literacy and familiarity with research advances in epilepsy genetics. Genetic epilepsy diagnoses now directly affect clinical care, and their importance will only increase as new targeted treatments continue to emerge. At the same time, new genetic insights challenge us to move from a deterministic view of genetic changes to a more nuanced appreciation of genetic risk within complex neurobiological systems that give rise to epilepsy.
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Affiliation(s)
- Colin A Ellis
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA; Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia
| | - Slavé Petrovski
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia; Centre for Genomics Research, Discovery Sciences, Research and Development Biopharmaceuticals, AstraZeneca, Cambridge, UK
| | - Samuel F Berkovic
- Epilepsy Research Centre, Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC, Australia.
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32
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Abstract
Dravet syndrome is a rare but severe epilepsy syndrome that begins in the first year of life with recurrent seizures triggered by fever that are typically prolonged and hemiclonic. The epilepsy is highly drug resistant. Although development is normal at onset, over time, most patients develop moderate-to-severe intellectual disability, behavior disorders, and a characteristic crouch gait. There is a significant mortality, predominantly owing to sudden unexpected death in epilepsy. Complete seizure control is rarely attainable. Initial therapy includes valproic acid and clobazam, but response is typically inadequate. The results of new drugs for Dravet syndrome, including stiripentol, cannabidiol, and fenfluramine, are very promising. Stiripentol was associated with a greater than 50% reduction in convulsive seizure frequency in 71% of cases, when added to valproic acid and clobazam, and also markedly reduced status epilepticus. Pharmaceutical-grade cannabidiol resulted in a median change in monthly motor seizures from baseline of - 36.5%. Fenfluramine was associated with a greater than 50% reduction in seizures of 70%, with one quarter of cases achieving near seizure freedom over the duration of the trial. These agents are generally well tolerated, with few patients discontinuing for adverse effects. There is limited evidence to date regarding improvement in cognition with these newer agents; however, a meaningful change is challenging to assess over short trial periods and requires longer follow-up studies. While current treatments focus predominantly on seizure control, newer therapies including genetic treatments and antisense oligonucleotides can target the SCN1A channelopathy, and thus, may also significantly impact the important co-morbidities associated with this syndrome.
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Affiliation(s)
- Elaine C Wirrell
- Child and Adolescent Neurology, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
| | - Rima Nabbout
- Hôpital Necker Enfants Malades, Université Paris Descartes, Paris, France
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Vidal S, Xiol C, Pascual-Alonso A, O'Callaghan M, Pineda M, Armstrong J. Genetic Landscape of Rett Syndrome Spectrum: Improvements and Challenges. Int J Mol Sci 2019; 20:ijms20163925. [PMID: 31409060 PMCID: PMC6719047 DOI: 10.3390/ijms20163925] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/08/2019] [Accepted: 08/10/2019] [Indexed: 02/06/2023] Open
Abstract
Rett syndrome (RTT) is an early-onset neurodevelopmental disorder that primarily affects females, resulting in severe cognitive and physical disabilities, and is one of the most prevalent causes of intellectual disability in females. More than fifty years after the first publication on Rett syndrome, and almost two decades since the first report linking RTT to the MECP2 gene, the research community's effort is focused on obtaining a better understanding of the genetics and the complex biology of RTT and Rett-like phenotypes without MECP2 mutations. Herein, we review the current molecular genetic studies, which investigate the genetic causes of RTT or Rett-like phenotypes which overlap with other genetic disorders and document the swift evolution of the techniques and methodologies employed. This review also underlines the clinical and genetic heterogeneity of the Rett syndrome spectrum and provides an overview of the RTT-related genes described to date, many of which are involved in epigenetic gene regulation, neurotransmitter action or RNA transcription/translation. Finally, it discusses the importance of including both phenotypic and genetic diagnosis to provide proper genetic counselling from a patient's perspective and the appropriate treatment.
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Affiliation(s)
- Silvia Vidal
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Clara Xiol
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Ainhoa Pascual-Alonso
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - M O'Callaghan
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- Neurology Service, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain
| | - Mercè Pineda
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
| | - Judith Armstrong
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain.
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain.
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, 08950 Barcelona, Spain.
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Clinically-relevant postzygotic mosaicism in parents and children with developmental disorders in trio exome sequencing data. Nat Commun 2019; 10:2985. [PMID: 31278258 PMCID: PMC6611863 DOI: 10.1038/s41467-019-11059-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/12/2019] [Indexed: 12/22/2022] Open
Abstract
Mosaic genetic variants can have major clinical impact. We systematically analyse trio exome sequence data from 4,293 probands from the DDD Study with severe developmental disorders for pathogenic postzygotic mosaicism (PZM) in the child or a clinically-unaffected parent, and use ultrahigh-depth sequencing to validate candidate mosaic variants. We observe that levels of mosaicism for small genetic variants are usually equivalent in both saliva and blood and ~3% of causative de novo mutations exhibit PZM; this is an important observation, as the sibling recurrence risk is extremely low. We identify parental PZM in 21 trios (0.5% of trios), resulting in a substantially increased sibling recurrence risk in future pregnancies. Together, these forms of mosaicism account for 40 (1%) diagnoses in our cohort. Likely child-PZM mutations occur equally on both parental haplotypes, and the penetrance of detectable mosaic pathogenic variants overall is likely to be less than half that of constitutive variants.
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Kordacka J, Zakrzewski K, Gruszka R, Witusik-Perkowska M, Taha J, Sikorska B, Liberski PP, Zakrzewska M. Sensitive detection of FGFR1 N546K mosaic mutation in patient with encephalocraniocutaneous lipomatosis and pilocytic astrocytoma. Am J Med Genet A 2019; 179:1622-1627. [PMID: 31173478 DOI: 10.1002/ajmg.a.61256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/28/2019] [Accepted: 05/21/2019] [Indexed: 11/12/2022]
Abstract
Encephalocraniocutaneous lipomatosis (ECCL) is a rare neurocutaneous disorder, with only about 100 cases reported worldwide. It is characterized by congenital lesions of the eye, skin, and central nervous system. Only recently, potential causative FGFR1 point mutations have been identified in brain tumors and cultured skin biopsies from patients with this condition. Here, we analyzed the molecular status of a patient with ECCL and a coexisting pilocytic astrocytoma with detected FGFR1 N546K mutation. The presence of the alteration in both affected and unaffected tissues has been evaluated using Sanger sequencing and droplet digital polymerase chain reaction (ddPCR) technique. The ddPCR analysis showed differential distribution of the alteration in all specimens, including unaffected and untreated samples. Therefore, we confirm that FGFR1 N546K is a plausible causative mutation of ECCL patients and could be associated with a risk of brain tumor development. We also show the usefulness of sensitive ddPCR method for detection of low levels of autosomal mosaic mutation in blood or swabs. We suggest that utilization of this method may improve the diagnostic process, especially when targeted therapies are considered.
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Affiliation(s)
- Joanna Kordacka
- Department of Molecular Pathology and Neuropathology, Medical University of Lodz, Lodz, Poland
| | - Krzysztof Zakrzewski
- Department of Neurosurgery, Polish Mother Memorial Hospital Research Institute in Lodz, Lodz, Poland
| | - Renata Gruszka
- Department of Molecular Pathology and Neuropathology, Medical University of Lodz, Lodz, Poland
| | | | - Joanna Taha
- Department of Pediatrics, Oncology and Hematology, Medical University of Lodz, Lodz, Poland
| | - Beata Sikorska
- Department of Molecular Pathology and Neuropathology, Medical University of Lodz, Lodz, Poland
| | - Paweł P Liberski
- Department of Molecular Pathology and Neuropathology, Medical University of Lodz, Lodz, Poland
| | - Magdalena Zakrzewska
- Department of Molecular Pathology and Neuropathology, Medical University of Lodz, Lodz, Poland
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de Lange IM, Weuring W, van 't Slot R, Gunning B, Sonsma ACM, McCormack M, de Kovel C, van Gemert LJJM, Mulder F, van Kempen MJA, Knoers NVAM, Brilstra EH, Koeleman BPC. Influence of common SCN1A promoter variants on the severity of SCN1A-related phenotypes. Mol Genet Genomic Med 2019; 7:e00727. [PMID: 31144463 PMCID: PMC6625088 DOI: 10.1002/mgg3.727] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/22/2019] [Accepted: 04/22/2019] [Indexed: 01/09/2023] Open
Abstract
Background Pathogenic variants in SCN1A cause variable epilepsy disorders with different disease severities. We here investigate whether common variation in the promoter region of the unaffected SCN1A allele could reduce normal expression, leading to a decreased residual function of Nav1.1, and therefore to more severe clinical outcomes in patients affected by pathogenic SCN1A variants. Methods Five different SCN1A promoter‐haplotypes were functionally assessed in SH‐SY5Y cells using Firefly and Renilla luciferase assays. The SCN1A promoter region was analyzed in a cohort of 143 participants with SCN1A pathogenic variants. Differences in clinical features and outcomes between participants with and without common variants in the SCN1A promoter‐region of their unaffected allele were investigated. Results All non‐wildtype haplotypes showed a significant reduction in luciferase expression, compared to the wildtype promoter‐region (65%–80%, p = 0.039–0.0023). No statistically significant differences in clinical outcomes were observed between patients with and without common promoter variants. However, patients with a wildtype promoter‐haplotype on their unaffected SCN1A allele showed a nonsignificant trend for milder phenotypes. Conclusion The nonsignificant observed trends in our study warrant replication studies in larger cohorts to explore the potential modifying role of these common SCN1A promoter‐haplotypes.
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Affiliation(s)
- Iris M de Lange
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Wout Weuring
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ruben van 't Slot
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Anja C M Sonsma
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mark McCormack
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Carolien de Kovel
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Flip Mulder
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marjan J A van Kempen
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Nine V A M Knoers
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Genetics, University Medical Center Groningen, Groningen, The Netherlands
| | - Eva H Brilstra
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bobby P C Koeleman
- Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
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Jansen S, van der Werf IM, Innes AM, Afenjar A, Agrawal PB, Anderson IJ, Atwal PS, van Binsbergen E, van den Boogaard MJ, Castiglia L, Coban-Akdemir ZH, van Dijck A, Doummar D, van Eerde AM, van Essen AJ, van Gassen KL, Guillen Sacoto MJ, van Haelst MM, Iossifov I, Jackson JL, Judd E, Kaiwar C, Keren B, Klee EW, Klein Wassink-Ruiter JS, Meuwissen ME, Monaghan KG, de Munnik SA, Nava C, Ockeloen CW, Pettinato R, Racher H, Rinne T, Romano C, Sanders VR, Schnur RE, Smeets EJ, Stegmann APA, Stray-Pedersen A, Sweetser DA, Terhal PA, Tveten K, VanNoy GE, de Vries PF, Waxler JL, Willing M, Pfundt R, Veltman JA, Kooy RF, Vissers LELM, de Vries BBA. De novo variants in FBXO11 cause a syndromic form of intellectual disability with behavioral problems and dysmorphisms. Eur J Hum Genet 2019; 27:738-746. [PMID: 30679813 DOI: 10.1038/s41431-018-0292-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 09/07/2018] [Accepted: 09/25/2018] [Indexed: 01/15/2023] Open
Abstract
Determining pathogenicity of genomic variation identified by next-generation sequencing techniques can be supported by recurrent disruptive variants in the same gene in phenotypically similar individuals. However, interpretation of novel variants in a specific gene in individuals with mild-moderate intellectual disability (ID) without recognizable syndromic features can be challenging and reverse phenotyping is often required. We describe 24 individuals with a de novo disease-causing variant in, or partial deletion of, the F-box only protein 11 gene (FBXO11, also known as VIT1 and PRMT9). FBXO11 is part of the SCF (SKP1-cullin-F-box) complex, a multi-protein E3 ubiquitin-ligase complex catalyzing the ubiquitination of proteins destined for proteasomal degradation. Twenty-two variants were identified by next-generation sequencing, comprising 2 in-frame deletions, 11 missense variants, 1 canonical splice site variant, and 8 nonsense or frameshift variants leading to a truncated protein or degraded transcript. The remaining two variants were identified by array-comparative genomic hybridization and consisted of a partial deletion of FBXO11. All individuals had borderline to severe ID and behavioral problems (autism spectrum disorder, attention-deficit/hyperactivity disorder, anxiety, aggression) were observed in most of them. The most relevant common facial features included a thin upper lip and a broad prominent space between the paramedian peaks of the upper lip. Other features were hypotonia and hyperlaxity of the joints. We show that de novo variants in FBXO11 cause a syndromic form of ID. The current series show the power of reverse phenotyping in the interpretation of novel genetic variances in individuals who initially did not appear to have a clear recognizable phenotype.
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Affiliation(s)
- Sandra Jansen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Ilse M van der Werf
- Department of Medical Genetics, University Hospital and University of Antwerp, Universiteitsplein 1, 2610, Antwerp, Belgium
| | - A Micheil Innes
- Alberta Children's Hospital Research Institute and Department of Medical Genetics, Cumming School of Medicine, University of Calgary, 2888 Shaganappi Trail NW, Calgary, AB, T3B 6A8, Canada
| | - Alexandra Afenjar
- Centre de Référence Déficiences Intellectuelles de Causes Rares, 75013, Paris, France.,APHP, GHUEP, Hôpital Armand Trousseau, Centre de Référence 'Malformations et maladies congénitales du cervelet', 75012, Paris, France
| | - Pankaj B Agrawal
- Divisions of Genetics and Genomics and Newborn Medicine, Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Ilse J Anderson
- The University of Tennessee Genetics Center, Knoxville, TN, 37920, USA
| | - Paldeep S Atwal
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Ellen van Binsbergen
- Department of Genetics, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Marie-José van den Boogaard
- Department of Genetics, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Lucia Castiglia
- Laboratory of Medical Genetics, Oasi Research Institute, 94018, Troina, Italy
| | - Zeynep H Coban-Akdemir
- Baylor-Hopkins Center for Mendelian Genomics, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Anke van Dijck
- Department of Medical Genetics, University Hospital and University of Antwerp, Universiteitsplein 1, 2610, Antwerp, Belgium
| | - Diane Doummar
- APHP, Service de Neurologie pédiatrique, Hôpital Armand Trousseau, Paris, France.,Sorbonne Université,GRC ConCer-LD, AP-HP, Hôpital Trousseau, Paris, France.,Service de neuropediatrie, Hôpital Trousseau, 26 avenue du dr Arnold Netter, 75012, Paris, France
| | - Albertien M van Eerde
- Department of Genetics, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Anthonie J van Essen
- Department of Genetics, University of Groningen, University Medical Center Groningen (UMCG), 9700 RB, Groningen, The Netherlands
| | - Koen L van Gassen
- Department of Genetics, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | | | - Mieke M van Haelst
- Department of Clinical Genetics, VU University Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Ivan Iossifov
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, NY, 11724, USA.,New York Genome Center, New York, NY, 10013, USA
| | - Jessica L Jackson
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Elizabeth Judd
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Charu Kaiwar
- Center for Individualized Medicine, Mayo Clinic, Scottsdale, AZ, 85259, USA.,Invitae, 1400 16th Street, San Francisco, CA, 94103, USA
| | - Boris Keren
- Département de Génétique, APHP, GH Pitié-Salpêtrière, Paris, 75013, France
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jolien S Klein Wassink-Ruiter
- Department of Genetics, University of Groningen, University Medical Center Groningen (UMCG), 9700 RB, Groningen, The Netherlands
| | - Marije E Meuwissen
- Department of Medical Genetics, University Hospital and University of Antwerp, Universiteitsplein 1, 2610, Antwerp, Belgium
| | | | - Sonja A de Munnik
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Caroline Nava
- Département de Génétique, APHP, GH Pitié-Salpêtrière, Paris, 75013, France.,INSERM, U 1127, CNRS UMR 7225, Institut du Cerveau et de la Moelle épinière, ICM, Sorbonne Universités, UPMC Université de Paris 06, 75013, Paris, France
| | - Charlotte W Ockeloen
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Rosa Pettinato
- Pediatrics and Medical Genetics, Oasi Research Institute - IRCCS, 94018, Troina, Italy
| | - Hilary Racher
- Alberta Children's Hospital Research Institute and Department of Medical Genetics, Cumming School of Medicine, University of Calgary, 2888 Shaganappi Trail NW, Calgary, AB, T3B 6A8, Canada.,Impact Genetics, 1100 Bennett Road, Bowmanville, ON, L1C 3K5, Canada
| | - Tuula Rinne
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Corrado Romano
- Pediatrics and Medical Genetics, Oasi Research Institute - IRCCS, 94018, Troina, Italy
| | - Victoria R Sanders
- Department of Pediatrics, Division of Genetics, Birth Defects and Metabolism, Ann and Robert H Lurie Children's Hospital of Chicago, 225 East Chicago Avenue, Chicago, IL, 60611, USA
| | | | - Eric J Smeets
- Department of Clinical Genetics, Maastricht University Medical Centre, Universiteitssingel 50, 9229 ER, Maastricht, The Netherlands
| | - Alexander P A Stegmann
- Department of Clinical Genetics, Maastricht University Medical Centre, Universiteitssingel 50, 9229 ER, Maastricht, The Netherlands
| | - Asbjørg Stray-Pedersen
- Baylor-Hopkins Center for Mendelian Genomics, Baylor College of Medicine, Houston, TX, 77030, USA.,Norwegian National Unit for Newborn Screening, Department of Pediatric and Adolescent Medicine, Oslo University Hospital, Pb 4950 Nydalen, 0424, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, 0318, Oslo, Norway
| | - David A Sweetser
- Division of Medical Genetics, Massachusetts General Hospital for Children, Boston, MA, 02114, USA
| | - Paulien A Terhal
- Department of Genetics, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Kristian Tveten
- Department of Medical Genetics, Telemark Hospital Trust, 3710, Skien, Norway
| | - Grace E VanNoy
- Divisions of Genetics and Genomics and Newborn Medicine, Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Petra F de Vries
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Jessica L Waxler
- Division of Medical Genetics, Massachusetts General Hospital for Children, Boston, MA, 02114, USA
| | - Marcia Willing
- Department of Pediatrics, Washington University School of Medicine, St Louis, MO, 63110, USA
| | - Rolph Pfundt
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Joris A Veltman
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.,Institute of Genetic Medicine, International Centre for Life, Newcastle University, Central Parkway, Newcastle, NE1 3BZ, UK
| | - R Frank Kooy
- Department of Medical Genetics, University Hospital and University of Antwerp, Universiteitsplein 1, 2610, Antwerp, Belgium
| | - Lisenka E L M Vissers
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Bert B A de Vries
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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Behavior problems and health-related quality of life in Dravet syndrome. Epilepsy Behav 2019; 90:217-227. [PMID: 30578097 DOI: 10.1016/j.yebeh.2018.11.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 11/22/2018] [Accepted: 11/22/2018] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Behavior problems in Dravet syndrome (DS) are common and can impact the lives of patients tremendously. The current study aimed to give more insight into (1) the prevalence of a wide range of specific behavior difficulties and aspects of health-related quality of life (HRQoL) in patients with DS compared with the general population (gp) and patients with epilepsy without DS, (2) the relations between these behavior problems and different aspects of HRQoL, and (3) the associations between seizure frequency, cognitive impairment (CI), behavior problems, and HRQoL, based on a conceptual model. METHODS One hundred and sixteen patients (aged between 2 and 67 years), affected by SCN1A-related seizures, were included in the study. Eighty-five were patients with DS, 31 were patients with epilepsy without DS. Behavior problems were measured using the Child/Adult Behavior Checklist (C/ABCL), HRQoL was measured using the Pediatric Quality of Life Inventory (PedsQL) Measurement Model. Other characteristics were obtained by clinical assessments, medical records, and semi-structured telephone interviews with parents. Comparisons between patients with DS, patients without DS, and the gp were calculated by the exact goodness of fit χ2 analyses, relations between subscales were analyzed using Pearson's correlations, and the conceptual model was tested in a path analysis. RESULTS (1) Patients with DS show significantly more behavior problems compared with the gp and patients with epilepsy without DS. A total of 56.5% of patients with DS scored in the borderline and clinical ranges for total behavior problems. Problems with attention were most prevalent; 62.3% of patients with DS scored in the borderline and clinical ranges. Health-related quality of life was significantly lower for patients with DS compared with the gp and patients without DS. Physical and social functioning scores were especially low and decreased even more in the older age categories. (2) Problems with attention, aggression, and withdrawn behavior were most related to social functioning. Somatic problems and anxiety/depression were most related to emotional functioning. (3) Cognitive impairment and behavior problems were both independent predictors of poorer HRQoL in patients with DS, with behavior problems being the strongest predictor. Seizure frequency was only indirectly related to HRQoL, mediated by cognitive impairment. IMPLICATIONS The high prevalence of behavior problems in DS and the significant impact on quality of life (QoL), independent of epilepsy-related factors, emphasize the need for active management and treatment of these problems and should be considered as part of the management plan.
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de Lange IM, Koudijs MJ, van ‘t Slot R, Sonsma ACM, Mulder F, Carbo EC, van Kempen MJA, Nijman IJ, Ernst RF, Savelberg SMC, Knoers NVAM, Brilstra EH, Koeleman BPC. Assessment of parental mosaicism in SCN1A-related epilepsy by single-molecule molecular inversion probes and next-generation sequencing. J Med Genet 2018; 56:75-80. [DOI: 10.1136/jmedgenet-2018-105672] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/24/2018] [Accepted: 09/30/2018] [Indexed: 01/08/2023]
Abstract
BackgroundDravet syndrome is a severe genetic encephalopathy, caused by pathogenic variants in SCN1A. Low-grade parental mosaicism occurs in a substantial proportion of families (7%–13%) and has important implications for recurrence risks. However, parental mosaicism can remain undetected by methods regularly used in diagnostics. In this study, we use single-molecule molecular inversion probes (smMIP), a technique with high sensitivity for detecting low-grade mosaic variants and high cost-effectiveness, to investigate the incidence of parental mosaicism of SCN1A variants in a cohort of 90 families and assess the feasibility of this technique.MethodsDeep sequencing of SCN1A was performed using smMIPs. False positive rates for each of the proband’s pathogenic variants were determined in 145 unrelated samples. If parents showed corresponding variant alleles at a significantly higher rate than the established noise ratio, mosaicism was confirmed by droplet digital PCR (ddPCR).ResultsSequence coverage of at least 100× at the location of the corresponding pathogenic variant was reached for 80 parent couples. The variant ratio was significantly higher than the established noise ratio in eight parent couples, of which four (5%) were regarded as true mosaics, based on ddPCR results. The false positive rate of smMIP analysis without ddPCR was therefore 50%. Three of these variants had previously been considered de novo in the proband by Sanger sequencing.ConclusionsmMIP technology combined withnext generation sequencing (NGS) performs better than Sanger sequencing in the detection of parental mosaicism. Because parental mosaicism has important implications for genetic counselling and recurrence risks, we stress the importance of implementing high-sensitivity NGS-based assays in standard diagnostics.
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40
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Myers KA, Johnstone DL, Dyment DA. Epilepsy genetics: Current knowledge, applications, and future directions. Clin Genet 2018; 95:95-111. [PMID: 29992546 DOI: 10.1111/cge.13414] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 07/03/2018] [Accepted: 07/06/2018] [Indexed: 12/12/2022]
Abstract
The rapid pace of disease gene discovery has resulted in tremendous advances in the field of epilepsy genetics. Clinical testing with comprehensive gene panels, exomes, and genomes are now available and have led to higher diagnostic rates and insights into the underlying disease processes. As such, the contribution to the care of patients by medical geneticists, neurogeneticists and genetic counselors are significant; the dysmorphic examination, the necessary pre- and post-test counseling, the selection of the appropriate next-generation sequencing-based test(s), and the interpretation of sequencing results require a care provider to have a comprehensive working knowledge of the strengths and limitations of the available testing technologies. As the underlying mechanisms of the encephalopathies and epilepsies are better understood, there may be opportunities for the development of novel therapies based on an individual's own specific genotype. Drug screening with in vitro and in vivo models of epilepsy can potentially facilitate new treatment strategies. The future of epilepsy genetics will also probably include other-omic approaches such as transcriptomes, metabolomes, and the expanded use of whole genome sequencing to further improve our understanding of epilepsy and provide better care for those with the disease.
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Affiliation(s)
- K A Myers
- Department of Pediatrics, University of McGill, Montreal, Canada.,Research Institute of the McGill University Health Centre, Montreal, Canada
| | - D L Johnstone
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - D A Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada.,Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, Canada
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de Lange IM, Gunning B, Sonsma ACM, van Gemert L, van Kempen M, Verbeek NE, Nicolai J, Knoers NVAM, Koeleman BPC, Brilstra EH. Influence of contraindicated medication use on cognitive outcome in Dravet syndrome and age at first afebrile seizure as a clinical predictor in SCN1A
-related seizure phenotypes. Epilepsia 2018; 59:1154-1165. [DOI: 10.1111/epi.14191] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Iris M. de Lange
- Department of Medical Genetics; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - Boudewijn Gunning
- The Epilepsy Institutes of The Netherlands Foundation (SEIN); Zwolle The Netherlands
| | - Anja C. M. Sonsma
- Department of Medical Genetics; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | | | - Marjan van Kempen
- Department of Medical Genetics; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - Nienke E. Verbeek
- Department of Medical Genetics; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - Joost Nicolai
- Academical Center of Epileptology; Maastricht and Heeze The Netherlands
| | - Nine V. A. M. Knoers
- Department of Medical Genetics; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - Bobby P. C. Koeleman
- Department of Medical Genetics; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - Eva H. Brilstra
- Department of Medical Genetics; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
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