1
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Hawkins NA, Speakes N, Kearney JA. Fine mapping and candidate gene analysis of Dravet syndrome modifier loci on mouse chromosomes 7 and 8. Mamm Genome 2024; 35:334-345. [PMID: 38862622 PMCID: PMC11329421 DOI: 10.1007/s00335-024-10046-3] [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: 04/15/2024] [Accepted: 05/21/2024] [Indexed: 06/13/2024]
Abstract
Dravet syndrome is a developmental and epileptic encephalopathy (DEE) characterized by intractable seizures, comorbidities related to developmental, cognitive, and motor delays, and a high mortality burden due to sudden unexpected death in epilepsy (SUDEP). Most Dravet syndrome cases are attributed to SCN1A haploinsufficiency, with genetic modifiers and environmental factors influencing disease severity. Mouse models with heterozygous deletion of Scn1a recapitulate key features of Dravet syndrome, including seizures and premature mortality; however, severity varies depending on genetic background. Here, we refined two Dravet survival modifier (Dsm) loci, Dsm2 on chromosome 7 and Dsm3 on chromosome 8, using interval-specific congenic (ISC) mapping. Dsm2 was complex and encompassed at least two separate loci, while Dsm3 was refined to a single locus. Candidate modifier genes within these refined loci were prioritized based on brain expression, strain-dependent differences, and biological relevance to seizures or epilepsy. High priority candidate genes for Dsm2 include Nav2, Ptpn5, Ldha, Dbx1, Prmt3 and Slc6a5, while Dsm3 has a single high priority candidate, Psd3. This study underscores the complex genetic architecture underlying Dravet syndrome and provides insights into potential modifier genes that could influence disease severity and serve as novel therapeutic targets.
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Affiliation(s)
- Nicole A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 East Superior St., Searle 8-510, Chicago, IL, 60611, USA
| | - Nathan Speakes
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 East Superior St., Searle 8-510, Chicago, IL, 60611, USA
| | - Jennifer A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 East Superior St., Searle 8-510, Chicago, IL, 60611, USA.
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2
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Syu YM, Lee IC, Lu JF, Hung PL, Hong SY, Yang MT, Liang JS. Insights into clinical phenotypes and treatment responses in a Small cohort of Taiwanese patients with SCN1A variants: A Preliminary study. Pediatr Neonatol 2024:S1875-9572(24)00134-7. [PMID: 39181834 DOI: 10.1016/j.pedneo.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 08/27/2024] Open
Abstract
BACKGROUND SCN1A channelopathy is the most well-known cause for epileptic encephalopathies and contributes to a wide phenotypic spectrum. The variable expressivity is troublesome for the interpretation of clinical significance and prognoses. To investigate the clinical manifestations, medications and outcomes of patients with SCN1A channelopathies, we conducted this observation retrospective study in Taiwan. METHODS A cohort consisting of 16 patients (5 males and 11 females) from multiple centers with identified SCN1A variants was investigated and phenotypically relevant factors were recorded. The variants were identified using NGS and confirmed by Sanger sequencing. A panel of 90 epileptic-related genes was used to identify SCN1A variants and to evaluate some of the potential SCN1A modifier genes. RESULTS The mean age of seizure onset was 10.4 months. Twelve of the sixteen patients (75%) had different degrees of neurocognitive sequela and psychobehavioral comorbidity in our cohort. Cognitive impairment was noted in all ten patients with Dravet syndrome (DS) and in two of the patients with non-DS phenotypes. A lower response rate to medications was also noted in patients with DS. Notably, a medication-specific tendency towards valproic acid (VPA), clobazam (CLB), and levetiracetam (LEV) was observed, revealing the effective pharmacotherapies for SCN1A-related seizures. An asymptomatic carrier with a reported pathogenic SCN1A variant was reviewed along with her monozygotic twin sister with DS. Nine novel SCN1A mutations are herein reported, eight of which being classified as pathogenic. CONCLUSION Our study revealed unfavorable outcomes for patients with SCN1A variants. Some patients with SCN1A channelopathy showed specific responsiveness to the pharmacotherapies previously either recommended or contraindicated for these patients. Our study also expands the genotype and provides valuable prognostic insights in patients with SCN1A channelopathy.
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Affiliation(s)
- Yu Min Syu
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City, 22021, Taiwan; Division of Genetics and Metabolism, Department of Pediatrics, MacKay Memorial Hospital, Taipei, 10449, Taiwan
| | - Inn-Chi Lee
- Division of Pediatric Neurology, Department of Pediatrics, Chung Shan Medical University Hospital, Taichung, 40201, Taiwan; Institute of Medicine, School of Medicine, Chung Shan Medical University, Taichung, 40201, Taiwan
| | - Jyh-Feng Lu
- School of Medicine, Fu Jen Catholic University, New Taipei City, 24206, Taiwan
| | - Pi-Lien Hung
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, 83301, Taiwan
| | - Syuan-Yu Hong
- Division of Pediatric Neurology, Department of Pediatrics, Children's Hospital, China Medical University Hospital, Taichung, 40447, Taiwan
| | - Ming-Tao Yang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City, 22021, Taiwan
| | - Jao-Shwann Liang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City, 22021, Taiwan; Department of Nursing, Asia Eastern University of Science and Technology, New Taipei City, 22030, Taiwan.
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Lu S, Niu Z, Qiao X. Exploring the Genotype-Phenotype Correlations in a Child with Inherited Seizure and Thrombocytopenia by Digenic Network Analysis. Genes (Basel) 2024; 15:1004. [PMID: 39202364 PMCID: PMC11353731 DOI: 10.3390/genes15081004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2024] [Revised: 07/24/2024] [Accepted: 07/27/2024] [Indexed: 09/03/2024] Open
Abstract
Understanding the correlation between genotype and phenotype remains challenging for modern genetics. Digenic network analysis may provide useful models for understanding complex phenotypes that traditional Mendelian monogenic models cannot explain. Clinical data, whole exome sequencing data, in silico, and machine learning analysis were combined to construct a digenic network that may help unveil the complex genotype-phenotype correlations in a child presenting with inherited seizures and thrombocytopenia. The proband inherited a maternal heterozygous missense variant in SCN1A (NM_001165963.4:c.2722G>A) and a paternal heterozygous missense variant in MYH9 (NM_002473.6:c.3323A>C). In silico analysis showed that these two variants may be pathogenic for inherited seizures and thrombocytopenia in the proband. Moreover, focusing on 230 epilepsy-associated genes and 35 thrombopoiesis genes, variant call format data of the proband were analyzed using machine learning tools (VarCoPP 2.0) and Digenic Effect predictor. A digenic network was constructed, and SCN1A and MYH9 were found to be core genes in the network. Further analysis showed that MYH9 might be a modifier of SCN1A, and the variant in MYH9 might not only influence the severity of SCN1A-related seizure but also lead to thrombocytopenia in the bone marrow. In addition, another eight variants might also be co-factors that account for the proband's complex phenotypes. Our data show that as a supplement to the traditional Mendelian monogenic model, digenic network analysis may provide reasonable models for the explanation of complex genotype-phenotype correlations.
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Affiliation(s)
| | | | - Xiaohong Qiao
- Department of Pediatrics, Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, Shanghai 200065, China; (S.L.); (Z.N.)
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Hawkins NA, Speakes N, Kearney JA. Fine Mapping and Candidate Gene Analysis of Dravet Syndrome Modifier Loci on Mouse Chromosomes 7 and 8. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589561. [PMID: 38659879 PMCID: PMC11042286 DOI: 10.1101/2024.04.15.589561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Dravet syndrome is a developmental and epileptic encephalopathy (DEE) characterized by intractable seizures, comorbidities related to developmental, cognitive, and motor delays, and a high mortality burden due to sudden unexpected death in epilepsy (SUDEP). Most Dravet syndrome cases are attributed to SCN1A haploinsufficiency, with genetic modifiers and environmental factors influencing disease severity. Mouse models with heterozygous deletion of Scn1a recapitulate key features of Dravet syndrome, including seizures and premature mortality; however, severity varies depending on genetic background. Here, we refined two Dravet survival modifier (Dsm) loci, Dsm2 on chromosome 7 and Dsm3 on chromosome 8, using interval-specific congenic (ISC) mapping. Dsm2 was complex and encompassed at least two separate loci, while Dsm3 was refined to a single locus. Candidate modifier genes within these refined loci were prioritized based on brain expression, strain-dependent differences, and biological relevance to seizures or epilepsy. High priority candidate genes for Dsm2 include Nav2, Ptpn5, Ldha, Dbx1, Prmt3 and Slc6a5, while Dsm3 has a single high priority candidate, Psd3. This study underscores the complex genetic architecture underlying Dravet syndrome and provides insights into potential modifier genes that could influence disease severity and serve as novel therapeutic targets.
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Affiliation(s)
- Nicole A. Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA 60611
| | - Nathan Speakes
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA 60611
| | - Jennifer A. Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA 60611
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Lersch R, Jannadi R, Grosse L, Wagner M, Schneider MF, von Stülpnagel C, Heinen F, Potschka H, Borggraefe I. Targeted Molecular Strategies for Genetic Neurodevelopmental Disorders: Emerging Lessons from Dravet Syndrome. Neuroscientist 2023; 29:732-750. [PMID: 35414300 PMCID: PMC10623613 DOI: 10.1177/10738584221088244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dravet syndrome is a severe developmental and epileptic encephalopathy mostly caused by heterozygous mutation of the SCN1A gene encoding the voltage-gated sodium channel α subunit Nav1.1. Multiple seizure types, cognitive deterioration, behavioral disturbances, ataxia, and sudden unexpected death associated with epilepsy are a hallmark of the disease. Recently approved antiseizure medications such as fenfluramine and cannabidiol have been shown to reduce seizure burden. However, patients with Dravet syndrome are still medically refractory in the majority of cases, and there is a high demand for new therapies aiming to improve behavioral and cognitive outcome. Drug-repurposing approaches for SCN1A-related Dravet syndrome are currently under investigation (i.e., lorcaserin, clemizole, and ataluren). New therapeutic concepts also arise from the field of precision medicine by upregulating functional SCN1A or by activating Nav1.1. These include antisense nucleotides directed against the nonproductive transcript of SCN1A with the poison exon 20N and against an inhibitory noncoding antisense RNA of SCN1A. Gene therapy approaches such as adeno-associated virus-based upregulation of SCN1A using a transcriptional activator (ETX101) or CRISPR/dCas technologies show promising results in preclinical studies. Although these new treatment concepts still need further clinical research, they offer great potential for precise and disease modifying treatment of Dravet syndrome.
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Affiliation(s)
- Robert Lersch
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Rawan Jannadi
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Leonie Grosse
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Matias Wagner
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute for Neurogenomics, Helmholtz Centre Munich, German Research Center for Health and Environment (GmbH), Munich, Germany
| | - Marius Frederik Schneider
- Metabolic Biochemistry, Biomedical Center Munich, Medical Faculty, Ludwig Maximilians University, Munich, Germany
- International Max Planck Research School (IMPRS) for Molecular Life Sciences, Planegg-Martinsried, Germany
| | - Celina von Stülpnagel
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Research Institute for Rehabilitation, Transition and Palliation, Paracelsus Medical Private University (PMU), Salzburg, Austria
| | - Florian Heinen
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig Maximilians University, Munich, Germany
| | - Ingo Borggraefe
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Comprehensive Epilepsy Center, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
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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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7
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Parenti I, Leitão E, Kuechler A, Villard L, Goizet C, Courdier C, Bayat A, Rossi A, Julia S, Bruel AL, Tran Mau-Them F, Nambot S, Lehalle D, Willems M, Lespinasse J, Ghoumid J, Caumes R, Smol T, El Chehadeh S, Schaefer E, Abi-Warde MT, Keren B, Afenjar A, Tabet AC, Levy J, Maruani A, Aledo-Serrano Á, Garming W, Milleret-Pignot C, Chassevent A, Koopmans M, Verbeek NE, Person R, Belles R, Bellus G, Salbert BA, Kaiser FJ, Mazzola L, Convers P, Perrin L, Piton A, Wiegand G, Accogli A, Brancati F, Benfenati F, Chatron N, Lewis-Smith D, Thomas RH, Zara F, Striano P, Lesca G, Depienne C. The different clinical facets of SYN1-related neurodevelopmental disorders. Front Cell Dev Biol 2022; 10:1019715. [PMID: 36568968 PMCID: PMC9773998 DOI: 10.3389/fcell.2022.1019715] [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: 08/15/2022] [Accepted: 10/20/2022] [Indexed: 12/13/2022] Open
Abstract
Synapsin-I (SYN1) is a presynaptic phosphoprotein crucial for synaptogenesis and synaptic plasticity. Pathogenic SYN1 variants are associated with variable X-linked neurodevelopmental disorders mainly affecting males. In this study, we expand on the clinical and molecular spectrum of the SYN1-related neurodevelopmental disorders by describing 31 novel individuals harboring 22 different SYN1 variants. We analyzed newly identified as well as previously reported individuals in order to define the frequency of key features associated with these disorders. Specifically, behavioral disturbances such as autism spectrum disorder or attention deficit hyperactivity disorder are observed in 91% of the individuals, epilepsy in 82%, intellectual disability in 77%, and developmental delay in 70%. Seizure types mainly include tonic-clonic or focal seizures with impaired awareness. The presence of reflex seizures is one of the most representative clinical manifestations related to SYN1. In more than half of the cases, seizures are triggered by contact with water, but other triggers are also frequently reported, including rubbing with a towel, fever, toothbrushing, fingernail clipping, falling asleep, and watching others showering or bathing. We additionally describe hyperpnea, emotion, lighting, using a stroboscope, digestive troubles, and defecation as possible triggers in individuals with SYN1 variants. The molecular spectrum of SYN1 variants is broad and encompasses truncating variants (frameshift, nonsense, splicing and start-loss variants) as well as non-truncating variants (missense substitutions and in-frame duplications). Genotype-phenotype correlation revealed that epileptic phenotypes are enriched in individuals with truncating variants. Furthermore, we could show for the first time that individuals with early seizures onset tend to present with severe-to-profound intellectual disability, hence highlighting the existence of an association between early seizure onset and more severe impairment of cognitive functions. Altogether, we present a detailed clinical description of the largest series of individuals with SYN1 variants reported so far and provide the first genotype-phenotype correlations for this gene. A timely molecular diagnosis and genetic counseling are cardinal for appropriate patient management and treatment.
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Affiliation(s)
- Ilaria Parenti
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Elsa Leitão
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Alma Kuechler
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Laurent Villard
- INSERM, MMG, Faculté de Médecine, Aix-Marseille University, Marseille, France
- Département de Génétique Médicale, APHM, Hôpital d'Enfants de La Timone, Marseille, France
| | - Cyril Goizet
- Service de Génétique Médicale, Bordeaux, France
- Centre de Référence Maladies Rares Neurogénétique, Service de Génétique Médicale, Bordeaux, France
- NRGEN Team, INCIA, CNRS UMR 5287, University of Bordeaux, Bordeaux, France
| | - Cécile Courdier
- Service de Génétique Médicale, Bordeaux, France
- Centre de Référence Maladies Rares Neurogénétique, Service de Génétique Médicale, Bordeaux, France
- NRGEN Team, INCIA, CNRS UMR 5287, University of Bordeaux, Bordeaux, France
| | - Allan Bayat
- Institute for Regional Health Services, University of Southern Denmark, Odense, Denmark
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Alessandra Rossi
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Dianalund, Denmark
- Pediatric Clinic, IRCCS Policlinico San Matteo Foundation, University of Pavia, Pavia, Italy
| | - Sophie Julia
- Service de Génétique Médicale, Pôle de Biologie, CHU de Toulouse - Hôpital Purpan, Toulouse, France
| | - Ange-Line Bruel
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
- UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Frédéric Tran Mau-Them
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
- UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Sophie Nambot
- UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Daphné Lehalle
- Unité Fonctionnelle Innovation en Diagnostic Génomique des Maladies Rares, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
- UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France
| | - Marjolaine Willems
- Department of Medical Genetics, Rare diseases and Personalized Medicine, CHU Montpellier, University of Montpellier, Montpellier, France
- Inserm U1298, INM, CHU Montpellier, University of Montpellier, Montpellier, France
| | - James Lespinasse
- Service de Cytogenetique, Centre Hospitalier de Chambéry, Chambéry, France
| | - Jamal Ghoumid
- Univ. Lille, ULR7364 RADEME, Lille, France
- CHU Lille, Clinique de Génétique, Guy Fontaine, Lille, France
| | - Roseline Caumes
- Univ. Lille, ULR7364 RADEME, Lille, France
- CHU Lille, Clinique de Génétique, Guy Fontaine, Lille, France
| | - Thomas Smol
- Univ. Lille, ULR7364 RADEME, Lille, France
- CHU Lille, Institut de Génétique Médicale, Lille, France
| | - Salima El Chehadeh
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - Elise Schaefer
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | | | - Boris Keren
- APHP, Département de Génétique, UF de Génomique du Développement, Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière, Sorbonne Université, Paris, France
| | - Alexandra Afenjar
- Département de Génétique, Centre de Référence déficiences Intellectuelles de Causes Rares, APHP, Hôpital Armand Trousseau, Sorbonne Université, Paris, France
| | | | - Jonathan Levy
- APHP, Département de Génétique, Hôpital Robert-Debré, Paris, France
| | - Anna Maruani
- Department of Child and Adolescent Psychiatry, Robert Debré Hospital, APHP, Paris, France
| | - Ángel Aledo-Serrano
- Epilepsy and Neurogenetics Program, Neurology Department, Ruber Internacional Hospital, Madrid, Spain
| | - Waltraud Garming
- Sozialpädiatrisches Zentrum, Kinder-und Jugendklinik Gelsenkirchen, Gelsenkirchen, Germany
| | | | - Anna Chassevent
- Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Marije Koopmans
- Department of Genetics, Utrecht University Medical Center, Utrecht, Netherlands
| | - Nienke E. Verbeek
- Department of Genetics, Utrecht University Medical Center, Utrecht, Netherlands
| | | | - Rebecca Belles
- Medical Genetics, Geisinger Medical Center, Danville, PA, United States
| | - Gary Bellus
- Medical Genetics, Geisinger Medical Center, Danville, PA, United States
| | - Bonnie A. Salbert
- Medical Genetics, Geisinger Medical Center, Danville, PA, United States
| | - Frank J. Kaiser
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
- Essener Zentrum für Seltene Erkrankungen (EZSE), Universitätsklinikum Essen, Essen, Germany
| | - Laure Mazzola
- Department of Neurology, University Hospital, Lyon Neuroscience Research Center (CRNL), INSERM U1028, CNRS UMR5292, Lyon, France
- Department of Neurology, University Hospital, Saint-Etienne, France
| | - Philippe Convers
- Department of Neurology, University Hospital, Lyon Neuroscience Research Center (CRNL), INSERM U1028, CNRS UMR5292, Lyon, France
- Department of Neurology, University Hospital, Saint-Etienne, France
| | - Laurine Perrin
- Department of Paediatric Physical Medicine and Rehabilitation, CHU Saint-Étienne, Hôpital Bellevue, Rhône-Alpes Reference Centre for Neuromuscular Diseases, Saint-Étienne, France
| | - Amélie Piton
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
- Centre National de la Recherche Scientifique, UMR7104, Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Gert Wiegand
- Division of Pediatric Neurology, Department of Pediatrics, Asklepios Klinik Nord-Heidberg, Hamburg, Germany
- Department of Pediatric and Adolescent Medicine II (Neuropediatrics, Social Pediatrics), University Medical Centre Schleswig-Holstein, Kiel, Germany
| | - Andrea Accogli
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Centre, Montreal, Qc, Canada
- Department of Human Genetics, Faculty of Medicine, McGill University, Montreal, Qc, Canada
| | - Francesco Brancati
- Department of Life, Human Genetics, Health and Environmental Sciences, University of L’Aquila, L’Aquila, Italy
- IRCCS San Raffaele Roma, Rome, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Geneva, Italy
- IRCCS Ospedale Policlinico San Martino, Geneva, Italy
| | - Nicolas Chatron
- Service de Genetique, Hospices Civils de Lyon, Bron, France
- Institute NeuroMyoGène, Laboratoire Physiopathologie et Génétique du Neurone et du Muscle, CNRS UMR 5261 -INSERM U1315, Université de Lyon - Université Claude Bernard Lyon 1, Lyon, France
| | - David Lewis-Smith
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom
- Department of Clinical Neurosciences, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, United Kingdom
| | - Rhys H. Thomas
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom
- Department of Clinical Neurosciences, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, United Kingdom
| | - Federico Zara
- IRCCS G. Gaslini, Genova, Italy
- Department of Neurology, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Pasquale Striano
- IRCCS G. Gaslini, Genova, Italy
- Department of Neurology, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Gaetan Lesca
- Service de Genetique, Hospices Civils de Lyon, Bron, France
- Institute NeuroMyoGène, Laboratoire Physiopathologie et Génétique du Neurone et du Muscle, CNRS UMR 5261 -INSERM U1315, Université de Lyon - Université Claude Bernard Lyon 1, Lyon, France
| | - Christel Depienne
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, Essen, Germany
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8
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Utility of Genetic Testing in Paediatric Epilepsy: Experience from a Low- Middle- Income Country. Epilepsy Behav Rep 2022; 20:100575. [DOI: 10.1016/j.ebr.2022.100575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/21/2022] Open
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9
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Hammer MF, Pan Y, Cumbay M, Pendziwiat M, Afawi Z, Goldberg-Stern H, Johnstone L, Helbig I, Cummins TR. Whole exome sequencing and co-expression analysis identify an SCN1A variant that modifies pathogenicity in a family with genetic epilepsy and febrile seizures plus. Epilepsia 2022; 63:1970-1980. [PMID: 35592948 PMCID: PMC10753192 DOI: 10.1111/epi.17296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 05/06/2022] [Accepted: 05/06/2022] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Family members carrying the same SCN1A variant often exhibit differences in the clinical severity of epilepsy. This variable expressivity suggests that other factors aside from the primary sodium channel variant influence the clinical manifestation. However, identifying such factors has proven challenging in humans. METHODS We perform whole exome sequencing (WES) in a large family in which an SCN1A variant (p.K1372E) is segregating that is associated with a broad spectrum of phenotypes ranging from lack of epilepsy, to febrile seizures and absence seizures, to Dravet syndrome. We assessed the hypothesis that the severity of the SCN1A-related phenotype was affected by alternate alleles at a modifier locus (or loci). RESULTS One of our top candidates identified by WES was a second variant in the SCN1A gene (p.L375S) that was shared exclusively by unaffected carriers of the K1372E allele. To test the hypothesized that L375S variant nullifies the loss-of-function effect of K1372E, we transiently expressed Nav1.1 carrying the two variants in HEK293T cells and compared their biophysical properties with the wild-type (WT) variant, and then co-expressed WT with K1372E or L375S with K1372E in equal quantity and tested the functional consequence. The data demonstrated that co-expression of the L375S and K1372E alleles reversed the loss-of-function property brought by the K1372E variant, whereas WT-K1372E co-expression remained partial loss-of-function. SIGNIFICANCE These results support the hypothesis that L375S counteracts the loss-of-function effect of K1372E such that individuals carrying both alleles in trans do not present epilepsy-related symptoms. We demonstrate that monogenic epilepsies with wide expressivity can be modified by additional variants in the disease gene, providing a novel framework for the gene-phenotype relationship in genetic epilepsies.
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Affiliation(s)
- Michael F. Hammer
- BIO5 Institute, University of Arizona, Tucson AZ USA
85716
- University of Arizona Genomics Core (UAGC), University of
Arizona, Tucson AZ USA 85716
| | - Yanling Pan
- Department of Biology, Indiana University-Purdue University
Indianapolis, Indianapolis IN 46202
| | - Medhane Cumbay
- Division of Biomedical Sciences, Marian University -
College of Osteopathic Medicine, Indianapolis, IN 46222
| | - Manuela Pendziwiat
- Department of Neuropediatrics, University Medical Center
Schleswig-Holstein Christian Albrechts University, Kiel, Germany
- Institute of Clinical Molecular Biology,
Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Zaid Afawi
- Center for Neuroscience, Ben-Gurion University of the
Negev, Be’er Sheva 8410402, Israel
| | | | - Laurel Johnstone
- University of Arizona Genomics Core (UAGC), University of
Arizona, Tucson AZ USA 85716
| | - Ingo Helbig
- Institute of Clinical Molecular Biology,
Christian-Albrechts-University of Kiel, Kiel, Germany
- Division of Neurology, Children’s Hospital of
Philadelphia, Philadelphia, PA, 19104 USA
- The Epilepsy NeuroGenetics Initiative (ENGIN),
Children’s Hospital of Philadelphia, Philadelphia, USA
- Department of Biomedical and Health Informatics (DBHi),
Children’s Hospital of Philadelphia, Philadelphia, PA, 19104 USA
- Department of Neurology, University of Pennsylvania,
Perelman School of Medicine, Philadelphia, PA, 19104 USA
| | - Theodore R. Cummins
- Department of Biology, Indiana University-Purdue University
Indianapolis, Indianapolis IN 46202
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10
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Phenotypic and Genotypic Spectrum of Early-Onset Developmental and Epileptic Encephalopathies-Data from a Romanian Cohort. Genes (Basel) 2022; 13:genes13071253. [PMID: 35886038 PMCID: PMC9322987 DOI: 10.3390/genes13071253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 02/01/2023] Open
Abstract
Early-onset developmental epileptic encephalopathy (DEE) refers to an age-specific, diverse group of epilepsy syndromes with electroclinical anomalies that are associated with severe cognitive, behavioral, and developmental impairments. Genetic DEEs have heterogeneous etiologies. This study includes 36 Romanian patients referred to the Regional Centre for Medical Genetics Dolj for genetic testing between 2017 and 2020. The patients had been admitted to and clinically evaluated at Doctor Victor Gomoiu Children’s Hospital and Prof. Dr. Alexandru Obregia Psychiatry Hospital in Bucharest. Panel testing was performed using the Illumina® TruSight™ One “clinical exome” (4811 genes), and the analysis focused on the known genes reported in DEEs and clinical concordance. The overall diagnostic rate was 25% (9/36 cases). Seven cases were diagnosed with Dravet syndrome (likely pathogenic/pathogenic variants in SCN1A) and two with Genetic Epilepsy with Febrile Seizures Plus (SCN1B). For the diagnosed patients, seizure onset was <1 year, and the seizure type was generalized tonic-clonic. Four additional plausible variants of unknown significance in SCN2A, SCN9A, and SLC2A1 correlated with the reported phenotype. Overall, we are reporting seven novel variants. Comprehensive clinical phenotyping is crucial for variant interpretation. Genetic assessment of patients with severe early-onset DEE can be a powerful diagnostic tool for clinicians, with implications for the management and counseling of the patients and their families.
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11
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Salvati A, Biagioni T, Ferrari AR, Lopergolo D, Brovedani P, Bartolini E. Different pilepsy course of a novel AHDC1 mutation in a female monozygotic twin pair. Seizure 2022; 99:127-130. [DOI: 10.1016/j.seizure.2022.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 10/18/2022] Open
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12
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McTague A, Brunklaus A, Barcia G, Varadkar S, Zuberi SM, Chatron N, Parrini E, Mei D, Nabbout R, Lesca G. Defining causal variants in rare epilepsies: an essential team effort between biomedical scientists, geneticists and epileptologists. Eur J Med Genet 2022; 65:104531. [PMID: 35618197 DOI: 10.1016/j.ejmg.2022.104531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 05/01/2022] [Accepted: 05/19/2022] [Indexed: 11/23/2022]
Abstract
In the last few years, with the advent of next generation sequencing (NGS), our knowledge of genes associated with monogenic epilepsies has significantly improved. NGS is also a powerful diagnostic tool for patients with epilepsy, through gene panels, exomes and genomes. This has improved diagnostic yield, reducing the time between the first seizure and a definitive molecular diagnosis. However, these developments have also increased the complexity of data interpretation, due to the large number of variants identified in a given patient and due to the phenotypic variability associated with many of the epilepsy-related genes. In this paper, we present examples of variant classification in "real life" clinic situations. We emphasize the importance of accurate phenotyping of the epilepsies including recognising variable/milder phenotypes and expansion of previously described phenotypes. There are some important issues specific to rare epilepsies - mosaicism and reduced penetrance - which affect genetic counselling. These challenges may be overcome through multidisciplinary meetings including epileptologists, pediatric neurologists, and clinical and molecular geneticists, in which every specialist learns from the others in a process which leads to for rapid and accurate diagnosis. This is an important milestone to achieve as targeted therapiesbased on the functional effects of pathogenic variants become available.
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Affiliation(s)
- Amy McTague
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, Member of the ERN EpiCARE, London, UK; Department of Neurology, Great Ormond Street Institute of Child Health, Member of the ERN EpiCARE, London, UK.
| | - Andreas Brunklaus
- The Pediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK; Institute of Health and Wellbeing, University of Glasgow, Member of the ERN EpiCARE, Glasgow, UK
| | - Giulia Barcia
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Member of the ERN EpiCARE, Paris, France
| | - Sophia Varadkar
- Department of Neurology, Great Ormond Street Institute of Child Health, Member of the ERN EpiCARE, London, UK
| | - Sameer M Zuberi
- The Pediatric Neurosciences Research Group, Royal Hospital for Children, Member of the ERN EpiCARE, Glasgow, UK; Institute of Health and Wellbeing, University of Glasgow, Member of the ERN EpiCARE, Glasgow, UK
| | - Nicolas Chatron
- Department of Medical Genetics, Lyon University Hospital, Université Claude Bernard Lyon 1, Member of the ERN EpiCARE, Lyon, France
| | - Elena Parrini
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital - University of Florence, Member of the ERN EpiCARE, Florence, Italy
| | - Davide Mei
- Pediatric Neurology, Neurogenetics, and Neurobiology Unit and Laboratories, Meyer Children's Hospital - University of Florence, Member of the ERN EpiCARE, Florence, Italy
| | - Rima Nabbout
- Department of Pediatric Neurology, Centre de Reference Epilepsies Rares, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Member of the ERN EpiCARE, Paris, France
| | - Gaetan Lesca
- Department of Medical Genetics, Lyon University Hospital, Université Claude Bernard Lyon 1, Member of the ERN EpiCARE, Lyon, France
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13
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Zhao X, Ning H, Wang Y, Zhao G, Mei S, Liu N, Wang C, Cai A, Wei E, Kong X. Genetic analysis and identification of novel variations in Chinese patients with pediatric epilepsy by whole-exome sequencing. Neurol Sci 2022; 43:4439-4451. [DOI: 10.1007/s10072-022-05953-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/12/2022] [Indexed: 11/28/2022]
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14
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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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15
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Kearney JA, Copeland-Hardin LD, Duarte S, Zachwieja NA, Eckart-Frank IK, Hawkins NA. Fine mapping and candidate gene analysis of a dravet syndrome modifier locus on mouse chromosome 11. Mamm Genome 2022; 33:565-574. [PMID: 35606653 DOI: 10.1007/s00335-022-09955-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/02/2022] [Indexed: 11/25/2022]
Abstract
Pathogenic variants in SCN1A result in a spectrum of phenotypes ranging from mild febrile seizures to Dravet syndrome, a severe infant-onset epileptic encephalopathy. Individuals with Dravet syndrome have developmental delays, elevated risk for sudden unexpected death in epilepsy (SUDEP), and have multiple seizure types that are often refractory to treatment. Although most Dravet syndrome variants arise de novo, there are cases where an SCN1A variant was inherited from mildly affected parents, as well as some individuals with de novo loss-of-function or truncation mutations that presented with milder phenotypes. This suggests that disease severity is influenced by other factors that modify expressivity of the primary mutation, which likely includes genetic modifiers. Consistent with this, the Scn1a+/- mouse model of Dravet syndrome exhibits strain-dependent variable phenotype severity. Scn1a+/- mice on the 129S6/SvEvTac (129) strain have no overt phenotype and a normal lifespan, while [C57BL/6Jx129]F1.Scn1a+/- mice have severe epilepsy with high rates of premature death. Low resolution genetic mapping identified several Dravet syndrome modifier (Dsm) loci responsible for the strain-dependent difference in survival of Scn1a+/- mice. To confirm the Dsm5 locus and refine its position, we generated interval-specific congenic strains carrying 129-derived chromosome 11 alleles on the C57BL/6J strain and localized Dsm5 to a 5.9 Mb minimal region. We then performed candidate gene analysis in the modifier region. Consideration of brain-expressed genes with expression or coding sequence differences between strains along with gene function suggested numerous strong candidates, including several protein coding genes and two miRNAs that may regulate Scn1a transcript.
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Affiliation(s)
- Jennifer A Kearney
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 E. Superior St., Searle 8-510, Chicago, IL, 60611, USA.
| | - Letonia D Copeland-Hardin
- Driskill Graduate Program in Life Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Samantha Duarte
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 E. Superior St., Searle 8-510, Chicago, IL, 60611, USA
| | - Nicole A Zachwieja
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 E. Superior St., Searle 8-510, Chicago, IL, 60611, USA
| | - Isaiah K Eckart-Frank
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 E. Superior St., Searle 8-510, Chicago, IL, 60611, USA
| | - Nicole A Hawkins
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, 320 E. Superior St., Searle 8-510, Chicago, IL, 60611, USA
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16
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Inherited Developmental and Epileptic Encephalopathies. Neurol Int 2021; 13:555-568. [PMID: 34842787 PMCID: PMC8628919 DOI: 10.3390/neurolint13040055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 01/13/2023] Open
Abstract
Epileptic encephalopathies often have a genetic etiology. The epileptic activity itself exerts a direct detrimental effect on neurodevelopment, which may add to the cognitive impairment induced by the underlying mutation (“developmental and epileptic encephalopathy”). The focus of this review is on inherited syndromes. The phenotypes of genetic disorders affecting ion channels, metabolic signalling, membrane trafficking and exocytosis, cell adhesion, cell growth and proliferation are discussed. Red flags suggesting family of genes or even specific genes are highlighted. The knowledge of the phenotypical spectrum can indeed prompt the clinician to suspect specific etiologies, expediting the diagnosis.
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17
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Rigamonti A, Mantero V, Peverelli L, Pagliarani S, Lucchiari S, Comi G, Gibertini S, Salmaggi A. p.Asn1180Ile mutation of SCN4A gene in an Italian family with myopathy and myotonic syndrome. Neurol Sci 2021; 42:5359-5363. [PMID: 34378097 DOI: 10.1007/s10072-021-05537-z] [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: 04/29/2021] [Accepted: 08/01/2021] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Mutations of the skeletal muscle sodium channel gene SCN4A are associated with several neuromuscular disorders including hyper/hypokaliemic periodic paralysis, paramyotonia congenita and sodium channel myotonia. These disorders are distinguished from dystrophic myotonias by the absence of progressive weakness and extramuscular systemic involvement. METHODS We present an Italian family with 2 subjects carrying a p.Asn1180Ile mutation in SCN4A gene showing a peculiar clinical picture characterized by the association of myopathic features and myotonia. RESULTS The clinical, electromyographic and histological findings of these patients are reported. The possible pathogenicity of the mutation was tested by three different software, all giving positive results. DISCUSSION This is the first report of a dominant, heterozygous mutation in SCN4A causing a complex phenotype of non-congenital myopathy and myotonic syndrome. We suggest that, in patients with myotonia and myopathy not related to dystrophic myotonias, the sequence analysis of SCN4A gene should be performed.
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Affiliation(s)
- Andrea Rigamonti
- Neurology Unit, Ospedale A. Manzoni, ASST Lecco, Via Dell'Eremo 9-11, 23900, Lecco, Italy.
| | - Vittorio Mantero
- Neurology Unit, Ospedale A. Manzoni, ASST Lecco, Via Dell'Eremo 9-11, 23900, Lecco, Italy
| | - Lorenzo Peverelli
- Neurology Unit, Ospedale Maggiore di Lodi, ASST Lodi, Largo Donatori del Sangue 1, 26900, Lodi, Italy
| | - Serena Pagliarani
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Via F. Sforza 35, 20122, Milano, Italy
| | - Sabrina Lucchiari
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Via F. Sforza 35, 20122, Milano, Italy
| | - Giacomo Comi
- Neuromuscular and Rare Diseases Unit, Foundation IRCSS Ca' Granda Ospedale Maggiore Policlinico, Via F. Sforza 35, 20122, Milano, Italy
| | - Sara Gibertini
- Muscle Cell Biology Laboratory, Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico "C. Besta", Via Celoria 11, 20133, Milano, Italy
| | - Andrea Salmaggi
- Neurology Unit, Ospedale A. Manzoni, ASST Lecco, Via Dell'Eremo 9-11, 23900, Lecco, Italy
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18
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Liu L, Liu F, Wang Q, Xie H, Li Z, Lu Q, Wang Y, Zhang M, Zhang Y, Picker J, Cui X, Zou L, Chen X. Confirming the contribution and genetic spectrum of de novo mutation in infantile spasms: Evidence from a Chinese cohort. Mol Genet Genomic Med 2021; 9:e1689. [PMID: 33951346 PMCID: PMC8222834 DOI: 10.1002/mgg3.1689] [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: 12/18/2020] [Revised: 03/24/2021] [Accepted: 03/30/2021] [Indexed: 01/21/2023] Open
Abstract
Objective We determined the yield, genetic spectrum, and actual origin of de novo mutations (DNMs) for infantile spasms (ISs) in a Chinese cohort. The efficacy of levetiracetam (LEV) for STXBP1‐related ISs was explored also. Methods Targeted sequencing of 153 epilepsy‐related candidate genes was applied to 289 Chinese patients with undiagnosed ISs. Trio‐based amplicon deep sequencing was used for all DNMs to distinguish somatic/mosaic mutations from germline ones. Results Total of 26 DNMs were identified from 289 recruited Chinese patients with undiagnosed ISs. Among them, 24 DNMs were interpreted as pathogenic mutations based on American College of Medical Genetics and Genomics guidelines, contributing to 8.3% (24/289) of diagnosis yield in the Chinese IS cohort. CDKL5 and STXBP1 are the top genes with recurrent DNMs, accounting for 3.1% (9/289) of yield. Further deep resequencing for the trio members showed that 22.7% (5/22) of DNMs are actually somatic in the proband or a parent. These somatic carriers presented milder seizure attacks than those with true germline DNMs. After treatment with LEV for half a year, three patients with DNM in STXBP1 showed improved clinical symptoms, including seizure‐free and normal electroencephalogram, except for a patient with a second DNM in DIAPH3. Significance Our study confirmed the contribution and genetic spectrum of DNMs in Chinese IS patients. Somatic mutation account for a quarter of DNMs in IS cases. Treatment with LEV improved the prognosis of STXBP1‐related ISs.
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Affiliation(s)
- Liying Liu
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Fang Liu
- Graduate School of Peking, Union Medical College, Beijing, China.,Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qiuhong Wang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Hua Xie
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Zhengchang Li
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China
| | - Qian Lu
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Yangyang Wang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Mengna Zhang
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China
| | - Yu Zhang
- Department of Lab Center, Capital Institute of Pediatrics, Beijing, China
| | - Jonathan Picker
- Division of Genetics & Genomics (Department of Medicine) and Department of Child & Adolescent Psychiatry, Boston Children's Hospital, Boston, MA, USA
| | - Xiaodai Cui
- Department of Lab Center, Capital Institute of Pediatrics, Beijing, China
| | - Liping Zou
- Department of Pediatrics, The First Medical Center of Chinese, PLA General Hospital, Beijing, China.,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China
| | - Xiaoli Chen
- Department of Medical Genetics, Capital Institute of Pediatrics, Beijing, China.,Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, China
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Sullo F, Pasquetti E, Patanè F, Lo Bianco M, Marino SD, Polizzi A, Falsaperla R, Ruggieri M, Zanghì A, Praticò AD. SCN1A and Its Related Epileptic Phenotypes. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1727260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractEpilepsy is one of the most common neurological disorders, with a lifetime incidence of 1 in 26. Approximately two-thirds of epilepsy has a substantial genetic component in its etiology. As a result, simultaneous screening for mutations in multiple genes and performing whole exome sequencing (WES) are becoming very frequent in the clinical evaluation of children with epilepsy. In this setting, mutations in voltage-gated sodium channel (SCN) α-subunit genes are the most commonly identified cause of epilepsy, with sodium channel genes (i.e., SCN1A, SCN2A, SCN8A) being the most frequently identified causative genes. SCN1A mutations result in a wide spectrum of epilepsy phenotypes ranging from simple febrile seizures to Dravet syndrome, a severe epileptic encephalopathy. In case of mutation of SCN1A, it is also possible to observe behavioral alterations, such as impulsivity, inattentiveness, and distractibility, which can be framed in an attention deficit hyperactivity disorder (ADHD) like phenotype. Despite more than 1,200 SCN1A mutations being reported, it is not possible to assess a clear phenotype–genotype correlations. Treatment remains a challenge and seizure control is often partial and transitory.
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Affiliation(s)
- Federica Sullo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Elisa Pasquetti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Francesca Patanè
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Simona D. Marino
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Agata Polizzi
- Chair of Pediatrics, Department of Educational Sciences, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
| | - Martino Ruggieri
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Antonio Zanghì
- Department of Medical and Surgical Sciences and Advanced Technology “G.F. Ingrassia,” University of Catania, Catania, Italy
| | - Andrea D. Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
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20
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Ma H, Guo Y, Chen Z, Wang L, Tang Z, Zhang J, Miao Q, Zhai Q. Mutations in the sodium channel genes SCN1A, SCN3A, and SCN9A in children with epilepsy with febrile seizures plus(EFS+). Seizure 2021; 88:146-152. [PMID: 33895391 DOI: 10.1016/j.seizure.2021.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To explore disease-causing gene mutations of epilepsy with febrile seizures plus (EFS+) in Southern Chinese Han population. METHODS Blood samples and clinical data were collected from 49 Southern Han Chinese patients with EFS+. Gene screening was performed using whole-exome sequencing and panel sequencing for 485 epilepsy-related genes. The pathogenicity of variants was evaluated based on ACMG scoring and assessment of clinical concordance. RESULTS We identified 10 putatively causative sodium channel gene variants in 49 patients with EFS+, including 8 variants in SCN1A (R500Q appeared twice), one in SCN3A and one in SCN9A. All these missense mutations were inherited from maternal or paternal and were evaluated to be of uncertain significance according to ACMG. The clinical features of patients were in concordance with the EFS+ phenotype of the mutated SCN1A, SCN3A and SCN9A gene. The clinical phenotypes of 11 probands with these gene variants included febrile seizures plus (FS+, n=7), Dravet Syndrome (n=3), FS+ with focal seizures (n=1). Three probands with SCN1A variants (R500Q located in the non-voltage areas, or G1711D in the pore-forming domain) developed severe Dravet syndrome. The affected individuals with the other 6 SCN1A variants located outside the pore-forming domain showed mild phenotypes. Novel SCN3A variant ((D1688Y) and SCN9A variant (R185H) were identified in two probands respectively and both of the probands had FS+. CONCLUSION The SCN1A, SCN3A, and SCN9A gene mutations might be a pathogenic cause of EFS+ in Southern Chinese Han population.
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Affiliation(s)
- Hongxia Ma
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China; Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong Province, China
| | - Yuxiong Guo
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Zhihong Chen
- Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Lingan Wang
- Department of Neurology and Rehabilitation, Guangdong Women and Children's Hospital, Guangzhou, Guangdong Province, China
| | - Zhihong Tang
- Department of Pediatrics, Dongguan City Maternal & Child Health Hospital, Dongguan, Guangdong Province, China
| | - Jingwen Zhang
- Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Qinfei Miao
- Shantou University, Shantou, Guangdong Province, China
| | - Qiongxiang Zhai
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China.
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21
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Mantegazza M, Cestèle S, Catterall WA. Sodium channelopathies of skeletal muscle and brain. Physiol Rev 2021; 101:1633-1689. [PMID: 33769100 DOI: 10.1152/physrev.00025.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Voltage-gated sodium channels initiate action potentials in nerve, skeletal muscle, and other electrically excitable cells. Mutations in them cause a wide range of diseases. These channelopathy mutations affect every aspect of sodium channel function, including voltage sensing, voltage-dependent activation, ion conductance, fast and slow inactivation, and both biosynthesis and assembly. Mutations that cause different forms of periodic paralysis in skeletal muscle were discovered first and have provided a template for understanding structure, function, and pathophysiology at the molecular level. More recent work has revealed multiple sodium channelopathies in the brain. Here we review the well-characterized genetics and pathophysiology of the periodic paralyses of skeletal muscle and then use this information as a foundation for advancing our understanding of mutations in the structurally homologous α-subunits of brain sodium channels that cause epilepsy, migraine, autism, and related comorbidities. We include studies based on molecular and structural biology, cell biology and physiology, pharmacology, and mouse genetics. Our review reveals unexpected connections among these different types of sodium channelopathies.
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Affiliation(s)
- Massimo Mantegazza
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France.,INSERM, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- Université Cote d'Azur, Valbonne-Sophia Antipolis, France.,CNRS UMR7275, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne-Sophia Antipolis, France
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22
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Sisodiya SM. Precision medicine and therapies of the future. Epilepsia 2020; 62 Suppl 2:S90-S105. [PMID: 32776321 PMCID: PMC8432144 DOI: 10.1111/epi.16539] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/24/2022]
Abstract
Precision medicine in the epilepsies has gathered much attention, especially with gene discovery pushing forward new understanding of disease biology. Several targeted treatments are emerging, some with considerable sophistication and individual‐level tailoring. There have been rare achievements in improving short‐term outcomes in a few very select patients with epilepsy. The prospects for further targeted, repurposed, or novel treatments seem promising. Along with much‐needed success, difficulties are also arising. Precision treatments do not always work, and sometimes are inaccessible or do not yet exist. Failures of precision medicine may not find their way to broader scrutiny. Precision medicine is not a new concept: It has been boosted by genetics and is often focused on genetically determined epilepsies, typically considered to be driven in an individual by a single genetic variant. Often the mechanisms generating the full clinical phenotype from such a perceived single cause are incompletely understood. The impact of additional genetic variation and other factors that might influence the clinical presentation represent complexities that are not usually considered. Precision success and precision failure are usually equally incompletely explained. There is a need for more comprehensive evaluation and a more rigorous framework, bringing together information that is both necessary and sufficient to explain clinical presentation and clinical responses to precision treatment in a precision approach that considers the full picture not only of the effects of a single variant, but also of its genomic and other measurable environment, within the context of the whole person. As we may be on the brink of a treatment revolution, progress must be considered and reasoned: One possible framework is proposed for the evaluation of precision treatments.
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Affiliation(s)
- Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,Chalfont Centre for Epilepsy, Bucks, UK
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23
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D'Adamo MC, Liantonio A, Conte E, Pessia M, Imbrici P. Ion Channels Involvement in Neurodevelopmental Disorders. Neuroscience 2020; 440:337-359. [PMID: 32473276 DOI: 10.1016/j.neuroscience.2020.05.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/16/2020] [Accepted: 05/19/2020] [Indexed: 12/14/2022]
Abstract
Inherited and sporadic mutations in genes encoding for brain ion channels, affecting membrane expression or biophysical properties, have been associated with neurodevelopmental disorders characterized by epilepsy, cognitive and behavioral deficits with significant phenotypic and genetic heterogeneity. Over the years, the screening of a growing number of patients and the functional characterization of newly identified mutations in ion channels genes allowed to recognize new phenotypes and to widen the clinical spectrum of known diseases. Furthermore, advancements in understanding disease pathogenesis at atomic level or using patient-derived iPSCs and animal models have been pivotal to orient therapeutic intervention and to put the basis for the development of novel pharmacological options for drug-resistant disorders. In this review we will discuss major improvements and critical issues concerning neurodevelopmental disorders caused by dysfunctions in brain sodium, potassium, calcium, chloride and ligand-gated ion channels.
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Affiliation(s)
- Maria Cristina D'Adamo
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta
| | | | - Elena Conte
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy
| | - Mauro Pessia
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Malta; Department of Physiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Paola Imbrici
- Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Italy.
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24
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Mantegazza M, Broccoli V. SCN1A/Na V 1.1 channelopathies: Mechanisms in expression systems, animal models, and human iPSC models. Epilepsia 2020; 60 Suppl 3:S25-S38. [PMID: 31904127 DOI: 10.1111/epi.14700] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 03/04/2019] [Indexed: 12/20/2022]
Abstract
Pathogenic SCN1A/NaV 1.1 mutations cause well-defined epilepsies, including genetic epilepsy with febrile seizures plus (GEFS+) and the severe epileptic encephalopathy Dravet syndrome. In addition, they cause a severe form of migraine with aura, familial hemiplegic migraine. Moreover, SCN1A/NaV 1.1 variants have been inferred as risk factors in other types of epilepsy. We review here the advancements obtained studying pathologic mechanisms of SCN1A/NaV 1.1 mutations with experimental systems. We present results gained with in vitro expression systems, gene-targeted animal models, and the induced pluripotent stem cell (iPSC) technology, highlighting advantages, limits, and pitfalls for each of these systems. Overall, the results obtained in the last two decades confirm that the initial pathologic mechanism of epileptogenic SCN1A/NaV 1.1 mutations is loss-of-function of NaV 1.1 leading to hypoexcitability of at least some types of γ-aminobutyric acid (GABA)ergic neurons (including cortical and hippocampal parvalbumin-positive and somatostatin-positive ones). Conversely, more limited results point to NaV 1.1 gain-of-function for familial hemiplegic migraine (FHM) mutations. Behind these relatively simple pathologic mechanisms, an unexpected complexity has been observed, in part generated by technical issues in experimental studies and in part related to intrinsically complex pathophysiologic responses and remodeling, which yet remain to be fully disentangled.
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Affiliation(s)
- Massimo Mantegazza
- University Cote d'Azur (UCA), CNRS UMR7275, INSERM, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Vania Broccoli
- San Raffaele Scientific Institute, Milan, Italy.,Institute of Neuroscience, National Research Council (CNR), Milan, Italy
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25
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A framework for an evidence-based gene list relevant to autism spectrum disorder. Nat Rev Genet 2020; 21:367-376. [PMID: 32317787 DOI: 10.1038/s41576-020-0231-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2020] [Indexed: 02/06/2023]
Abstract
Autism spectrum disorder (ASD) is often grouped with other brain-related phenotypes into a broader category of neurodevelopmental disorders (NDDs). In clinical practice, providers need to decide which genes to test in individuals with ASD phenotypes, which requires an understanding of the level of evidence for individual NDD genes that supports an association with ASD. Consensus is currently lacking about which NDD genes have sufficient evidence to support a relationship to ASD. Estimates of the number of genes relevant to ASD differ greatly among research groups and clinical sequencing panels, varying from a few to several hundred. This Roadmap discusses important considerations necessary to provide an evidence-based framework for the curation of NDD genes based on the level of information supporting a clinically relevant relationship between a given gene and ASD.
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26
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Groome JR, Bayless-Edwards L. Roles for Countercharge in the Voltage Sensor Domain of Ion Channels. Front Pharmacol 2020; 11:160. [PMID: 32180723 PMCID: PMC7059764 DOI: 10.3389/fphar.2020.00160] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/07/2020] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated ion channels share a common structure typified by peripheral, voltage sensor domains. Their S4 segments respond to alteration in membrane potential with translocation coupled to ion permeation through a central pore domain. The mechanisms of gating in these channels have been intensely studied using pioneering methods such as measurement of charge displacement across a membrane, sequencing of genes coding for voltage-gated ion channels, and the development of all-atom molecular dynamics simulations using structural information from prokaryotic and eukaryotic channel proteins. One aspect of this work has been the description of the role of conserved negative countercharges in S1, S2, and S3 transmembrane segments to promote sequential salt-bridge formation with positively charged residues in S4 segments. These interactions facilitate S4 translocation through the lipid bilayer. In this review, we describe functional and computational work investigating the role of these countercharges in S4 translocation, voltage sensor domain hydration, and in diseases resulting from countercharge mutations.
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Affiliation(s)
- James R. Groome
- Department of Biological Sciences, Idaho State University, Pocatello, ID, United States
| | - Landon Bayless-Edwards
- Department of Biological Sciences, Idaho State University, Pocatello, ID, United States
- Oregon Health and Sciences University School of Medicine, Portland, OR, United States
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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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Scheffer IE, Nabbout R. SCN1A‐related phenotypes: Epilepsy and beyond. Epilepsia 2019; 60 Suppl 3:S17-S24. [DOI: 10.1111/epi.16386] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Ingrid E. Scheffer
- Departments of Medicine and Paediatrics Austin Health and Royal Children’s Hospital Florey and Murdoch Children’s Research Institute The University of Melbourne Melbourne VIC Australia
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies Department of Paediatric Neurology Necker Enfants Malades Hospital Imagine Institute U1163 Paris Descartes University Paris France
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29
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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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30
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AlSaif S, Umair M, Alfadhel M. Biallelic SCN2A Gene Mutation Causing Early Infantile Epileptic Encephalopathy: Case Report and Review. J Cent Nerv Syst Dis 2019; 11:1179573519849938. [PMID: 31205438 PMCID: PMC6537489 DOI: 10.1177/1179573519849938] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 04/20/2019] [Indexed: 01/13/2023] Open
Abstract
The voltage-gated sodium channel neuronal type 2 alpha subunit (Navα1.2) encoded by the SCN2A gene causes early infantile epileptic encephalopathy (EIEE) inherited in an autosomal dominant manner. Clinically, it has variable presentations, ranging from benign familial infantile seizures (BFIS) to severe EIEE. Diagnosis is achieved through molecular DNA testing of the SCN2A gene. Herein, we report on a 30-month-old Saudi girl who presented on the fourth day of life with EIEE, normal brain magnetic resonance imaging (MRI), normal electroencephalography (EEG), and well-controlled seizures. Genetic investigation revealed a novel homozygous missense mutation (c.5242A > G; p.Asn1748Asp) in the SCN2A gene (NM_001040142.1). This is the first reported autosomal recessive inheritance of a disease allele in the SCN2A and therefore expands the molecular and inheritance spectrum of the SCN2A gene defects.
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Affiliation(s)
- Shahad AlSaif
- College of Medicine, King Saud bin Abdulaziz University for Health Science, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Muhammad Umair
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud bin Abdulaziz University for Health Science, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - Majid Alfadhel
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud bin Abdulaziz University for Health Science, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia.,Division of Genetics, Department of Pediatrics, King Saud bin Abdulaziz University for Health Science, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (NGHA), Riyadh, Saudi Arabia
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31
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Salgueiro-Pereira AR, Duprat F, Pousinha PA, Loucif A, Douchamps V, Regondi C, Ayrault M, Eugie M, Stunault MI, Escayg A, Goutagny R, Gnatkovsky V, Frassoni C, Marie H, Bethus I, Mantegazza M. A two-hit story: Seizures and genetic mutation interaction sets phenotype severity in SCN1A epilepsies. Neurobiol Dis 2019; 125:31-44. [DOI: 10.1016/j.nbd.2019.01.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/14/2018] [Accepted: 01/14/2019] [Indexed: 01/07/2023] Open
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32
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Gonsales MC, Montenegro MA, Preto P, Guerreiro MM, Coan AC, Quast MP, Carvalho BS, Lopes-Cendes I. Multimodal Analysis of SCN1A Missense Variants Improves Interpretation of Clinically Relevant Variants in Dravet Syndrome. Front Neurol 2019; 10:289. [PMID: 31001185 PMCID: PMC6455056 DOI: 10.3389/fneur.2019.00289] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/06/2019] [Indexed: 01/27/2023] Open
Abstract
Objective: We aimed to improve the classification of SCN1A missense variants in patients with Dravet syndrome (DS) by combining and modifying the current variants classification criteria to minimize inconclusive test results. Methods: We established a score classification workflow based on evidence of pathogenicity to adapt the classification of DS-related SCN1A missense variants. In addition, we compiled the variants reported in the literature and our cohort and assessed the proposed pathogenic classification criteria. We combined information regarding previously established pathogenic amino acid changes, mode of inheritance, population-specific allele frequencies, localization within protein domains, and deleterious effect prediction analysis. Results: Our meta-analysis showed that 46% (506/1,101) of DS-associated SCN1A variants are missense. We applied the score classification workflow and 56.5% (286/506) of the variants had their classification changed from VUS: 17.8% (90/506) into "pathogenic" and 38.7% (196/506) as "likely pathogenic." Conclusion: Our results indicate that using multimodal analysis seems to be the best approach to interpret the pathogenic impact of SCN1A missense changes for the molecular diagnosis of patients with DS. By applying the proposed workflow, most DS related SCN1A variants had their classification improved.
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Affiliation(s)
- Marina C. Gonsales
- Department of Medical Genetics and Genomic Medicine, School of Medical Sciences, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
| | - Maria Augusta Montenegro
- Department of Neurology, School of Medical Sciences, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
| | - Paula Preto
- Department of Neurology, School of Medical Sciences, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
| | - Marilisa M. Guerreiro
- Department of Neurology, School of Medical Sciences, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
| | - Ana Carolina Coan
- Department of Neurology, School of Medical Sciences, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
| | - Monica Paiva Quast
- Department of Statistics, Institute of Mathematics, Statistics and Scientific Computing, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
| | - Benilton S. Carvalho
- Department of Statistics, Institute of Mathematics, Statistics and Scientific Computing, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
| | - Iscia Lopes-Cendes
- Department of Medical Genetics and Genomic Medicine, School of Medical Sciences, The Brazilian Institute of Neuroscience and Neurotecnology, University of Campinas, Campinas, Brazil
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33
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Abstract
Although the majority of seizures in neonates are related to acute brain injury, a substantial minority are the first symptom of a neonatal-onset epilepsy often linked to a pathogenic genetic variant. Historically, studies on neonatal seizures including treatment response and long-term consequences have lumped all etiologies together. However, etiology has been consistently shown to be the most important determinant of outcome. In the past few years, an increasing number of monogenic disorders have been described and might explain up to a third of neonatal-onset epilepsy syndromes previously included under the umbrella of Ohtahara syndrome and early myoclonic encephalopathy. In this chapter, we define the concept of genetic epilepsy and review the classification. Then, we review the most relevant monogenic neonatal-onset epilepsies, detail their underlying pathophysiologic mechanisms, and present their electroclinical phenotypes. We highlight that, in some cases, such as neonates with KCNQ2 or KCNT1 gene mutations, the early recognition of the electroclinical phenotype can lead to targeted diagnostic testing and precision medicine treatment, enabling the possibility of improved outcome.
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Jiang T, Shen Y, Chen H, Yuan Z, Mao S, Gao F. Clinical and molecular analysis of epilepsy-related genes in patients with Dravet syndrome. Medicine (Baltimore) 2018; 97:e13565. [PMID: 30558019 PMCID: PMC6320057 DOI: 10.1097/md.0000000000013565] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Dravet syndrome is considered to be one of the most severe types of genetic epilepsy. Mutations in SCN1A gene have been found to be responsible for at least 80% of patients with Dravet syndrome, and 90% of these mutations arise de novo. The variable clinical phenotype is commonly observed among these patients with SCN1A mutations, suggesting that genetic modifiers may influence the phenotypic expression of Dravet syndrome. In the present study, we described the clinical, pathological, and molecular characteristics of 13 Han Chinese pedigrees clinically diagnosed with Dravet syndrome. By targeted-exome sequencing, bioinformatics analysis and Sanger sequencing verification, 11 variants were identified in SCN1A gene among 11 pedigrees including 7 missense mutations, 2 splice site mutations, and 2 frameshift mutations (9 novel variants and 2 reported mutations). Particularly, 2 of these Dravet syndrome patients with SCN1A variants also harbored SCN9A, KCNQ2, or SLC6A8 variants. In addition, 2 subjects were failed to detect any pathogenic mutations in SCN1A and other epilepsy-related genes. These data suggested that SCN1A variants account for about 84.6% of Dravet syndrome in our cohort. This study expanded the mutational spectrum for the SCN1A gene, and also provided clinical and genetic evidence for the hypothesis that genetic modifiers may contribute to the variable manifestation of Dravet syndrome patients with SCN1A mutations. Thus, targeted-exome sequencing will make it possible to detect the interactions of epilepsy-related genes and reveal their modification on the severity of SCN1A mutation-related Dravet syndrome.
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Affiliation(s)
- TieJia Jiang
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Yaping Shen
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Huai Chen
- Hangzhou Red Cross Hospital, Hangzhou, China
| | - Zhefeng Yuan
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Shanshan Mao
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
| | - Feng Gao
- Department of Neurology, The Children's Hospital of Zhejiang University School of Medicine
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35
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Scheffer IE, Berkovic S, Capovilla G, Connolly MB, French J, Guilhoto L, Hirsch E, Jain S, Mathern GW, Moshé SL, Nordli DR, Perucca E, Tomson T, Wiebe S, Zhang YH, Zuberi SM. ILAE-Klassifikation der Epilepsien: Positionspapier der ILAE-Kommission für Klassifikation und Terminologie. ZEITSCHRIFT FUR EPILEPTOLOGIE 2018. [DOI: 10.1007/s10309-018-0218-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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36
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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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Liu J, Tong L, Song S, Niu Y, Li J, Wu X, Zhang J, Zai CC, Luo F, Wu J, Li H, Wong AHC, Sun R, Liu F, Li B. Novel and de novo mutations in pediatric refractory epilepsy. Mol Brain 2018; 11:48. [PMID: 30185235 PMCID: PMC6125990 DOI: 10.1186/s13041-018-0392-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/27/2018] [Indexed: 12/19/2022] Open
Abstract
Pediatric refractory epilepsy is a broad phenotypic spectrum with great genetic heterogeneity. Next-generation sequencing (NGS) combined with Sanger sequencing could help to understand the genetic diversity and underlying disease mechanisms in pediatric epilepsy. Here, we report sequencing results from a cohort of 172 refractory epilepsy patients aged 0-14 years. The pathogenicity of identified variants was evaluated in accordance with the American College of Medical Genetics and Genomics (ACMG) criteria. We identified 43 pathogenic or likely pathogenic variants in 40 patients (23.3%). Among these variants, 74.4% mutations (32/43) were de novo and 60.5% mutations (26/43) were novel. Patients with onset age of seizures ≤12 months had higher yields of deleterious variants compared to those with onset age of seizures > 12 months (P = 0.006). Variants in ion channel genes accounted for the greatest functional gene category (55.8%), with SCN1A coming first (16/43). 81.25% (13/16) of SCN1A mutations were de novo and 68.8% (11/16) were novel in Dravet syndrome. Pathogenic or likely pathogenic variants were found in the KCNQ2, STXBP1, SCN2A genes in Ohtahara syndrome. Novel deleterious variants were also found in West syndrome, Doose syndrome and glucose transporter type 1 deficiency syndrome patients. One de novo MECP2 mutation were found in a Rett syndrome patient. TSC1/TSC2 variants were found in 60% patients with tuberous sclerosis complex patients. Other novel mutations detected in unclassified epilepsy patients involve the SCN8A, CACNA1A, GABRB3, GABRA1, IQSEC2, TSC1, VRK2, ATP1A2, PCDH19, SLC9A6 and CHD2 genes. Our study provides novel insights into the genetic origins of pediatric epilepsy and represents a starting-point for further investigations into the molecular pathophysiology of pediatric epilepsy that could eventually lead to better treatments.
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Affiliation(s)
- Jing Liu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Lili Tong
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Shuangshuang Song
- Qilu Children's hospital of Shandong University, Jinan, Shandong, People's Republic of China
| | - Yue Niu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Jun Li
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Xiu Wu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Jie Zhang
- MyGenostics Inc., Beijing, People's Republic of China
| | - Clement C Zai
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Fang Luo
- MyGenostics Inc., Beijing, People's Republic of China
| | - Jian Wu
- MyGenostics Inc., Beijing, People's Republic of China
| | - Haiyin Li
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Albert H C Wong
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Ruopeng Sun
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China.,Shandong University, Jinan, Shandong, People's Republic of China
| | - Fang Liu
- Shandong University, Jinan, Shandong, People's Republic of China.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada
| | - Baomin Li
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, Shandong, People's Republic of China. .,Shandong University, Jinan, Shandong, People's Republic of China.
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38
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Zima L, Ceulemans S, Reiner G, Galosi S, Chen D, Sahagian M, Haas RH, Hyland K, Friedman J. Paroxysmal motor disorders: expanding phenotypes lead to coalescing genotypes. Ann Clin Transl Neurol 2018; 5:996-1010. [PMID: 30128325 PMCID: PMC6093839 DOI: 10.1002/acn3.597] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 11/07/2022] Open
Abstract
Paroxysmal movement disorders encompass varied motor phenomena. Less recognized features and wide phenotypic and genotypic heterogeneity are impediments to straightforward molecular diagnosis. We describe a family with episodic ataxia type 1, initially mis‐characterized as paroxysmal dystonia to illustrate this diagnostic challenge. We summarize clinical features in affected individuals to highlight underappreciated aspects and provide comprehensive phenotypic description of the rare familial KCNA1 mutation. Delayed diagnosis in this family is emblematic of the broader challenge of diagnosing other paroxysmal motor disorders. We summarize genotypic and phenotypic overlap and provide a suggested diagnostic algorithm for approaching patients with these conditions.
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Affiliation(s)
- Laura Zima
- University of Nebraska Medical Center Omaha Nebraska
| | - Sophia Ceulemans
- Division of Neurology Rady Children's Hospital San Diego California
| | - Gail Reiner
- Division of Neurology Rady Children's Hospital San Diego California.,Department of Neurosciences University of California San Diego San Diego California
| | - Serena Galosi
- Division of Neurology Rady Children's Hospital San Diego California.,Department of Neurosciences University of California San Diego San Diego California.,Department of Human Neuroscience Child Neurology and Psychiatry Sapienza University Rome Italy
| | - Dillon Chen
- Division of Neurology Rady Children's Hospital San Diego California.,Department of Neurosciences University of California San Diego San Diego California
| | - Michelle Sahagian
- Division of Neurology Rady Children's Hospital San Diego California.,Department of Neurosciences University of California San Diego San Diego California
| | - Richard H Haas
- Division of Neurology Rady Children's Hospital San Diego California.,Department of Pediatrics University of California San Diego San Diego California.,Department of Neurosciences University of California San Diego San Diego California
| | - Keith Hyland
- Medical Neurogenetics Laboratories Atlanta Georgia
| | - Jennifer Friedman
- Division of Neurology Rady Children's Hospital San Diego California.,Department of Pediatrics University of California San Diego San Diego California.,Department of Neurosciences University of California San Diego San Diego California.,Rady Children's Institute for Genomic Medicine San Diego California
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39
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Ye AY, Dou Y, Yang X, Wang S, Huang AY, Wei L. A model for postzygotic mosaicisms quantifies the allele fraction drift, mutation rate, and contribution to de novo mutations. Genome Res 2018; 28:943-951. [PMID: 29875290 PMCID: PMC6028137 DOI: 10.1101/gr.230003.117] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 05/02/2018] [Indexed: 12/14/2022]
Abstract
The allele fraction (AF) distribution, occurrence rate, and evolutionary contribution of postzygotic single-nucleotide mosaicisms (pSNMs) remain largely unknown. In this study, we developed a mathematical model to describe the accumulation and AF drift of pSNMs during the development of multicellular organisms. By applying the model, we quantitatively analyzed two large-scale data sets of pSNMs identified from human genomes. We found that the postzygotic mutation rate per cell division during early embryogenesis, especially during the first cell division, was higher than the average mutation rate in either male or female gametes. We estimated that the stochastic cell death rate per cell cleavage during human embryogenesis was ∼5%, and parental pSNMs occurring during the first three cell divisions contributed to ∼10% of the de novo mutations observed in children. We further demonstrated that the genomic profiles of pSNMs could be used to measure the divergence distance between tissues. Our results highlight the importance of pSNMs in estimating recurrence risk and clarified the quantitative relationship between postzygotic and de novo mutations.
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Affiliation(s)
- Adam Yongxin Ye
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China.,Peking-Tsinghua Center for Life Sciences, Beijing 100871, People's Republic of China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, People's Republic of China
| | - Yanmei Dou
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China.,National Institute of Biological Sciences, Beijing 102206, People's Republic of China
| | - Xiaoxu Yang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Sheng Wang
- National Institute of Biological Sciences, Beijing 102206, People's Republic of China.,College of Biological Sciences, China Agricultural University, Beijing 100094, People's Republic of China
| | - August Yue Huang
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Liping Wei
- Center for Bioinformatics, State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
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40
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Abstract
Epilepsy affects all age groups and is one of the most common and most disabling neurological disorders. The accurate diagnosis of seizures is essential as some patients will be misdiagnosed with epilepsy, whereas others will receive an incorrect diagnosis. Indeed, errors in diagnosis are common, and many patients fail to receive the correct treatment, which often has severe consequences. Although many patients have seizure control using a single medication, others require multiple medications, resective surgery, neuromodulation devices or dietary therapies. In addition, one-third of patients will continue to have uncontrolled seizures. Epilepsy can substantially impair quality of life owing to seizures, comorbid mood and psychiatric disorders, cognitive deficits and adverse effects of medications. In addition, seizures can be fatal owing to direct effects on autonomic and arousal functions or owing to indirect effects such as drowning and other accidents. Deciphering the pathophysiology of epilepsy has advanced the understanding of the cellular and molecular events initiated by pathogenetic insults that transform normal circuits into epileptic circuits (epileptogenesis) and the mechanisms that generate seizures (ictogenesis). The discovery of >500 genes associated with epilepsy has led to new animal models, more precise diagnoses and, in some cases, targeted therapies.
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Affiliation(s)
- Orrin Devinsky
- Departments of Neurology, Neuroscience, Neurosurgery and Psychiatry, NYU School of Medicine, New York, NY, USA
| | - Annamaria Vezzani
- Laboratory of Experimental Neurology, Department of Neuroscience, IRCCS 'Mario Negri' Institute for Pharmacological Research, Milan, Italy
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia.,Departments of Neurology and Medicine, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Nathalie Jette
- Department of Neurology and Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, and Department of Neurology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia.,Departments of Neurology and Medicine, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
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41
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Lesca G. Aspetti genetici delle epilessie. Neurologia 2018. [DOI: 10.1016/s1634-7072(18)41286-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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42
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de Lange IM, Koudijs MJ, van 't Slot R, Gunning B, Sonsma ACM, van Gemert LJJM, Mulder F, Carbo EC, van Kempen MJA, Verbeek NE, Nijman IJ, Ernst RF, Savelberg SMC, Knoers NVAM, Brilstra EH, Koeleman BPC. Mosaicism of de novo pathogenic SCN1A
variants in epilepsy is a frequent phenomenon that correlates with variable phenotypes. Epilepsia 2018; 59:690-703. [DOI: 10.1111/epi.14021] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Iris M. de Lange
- Department of Genetics; Center for Molecular Medicine; University Medical Center Utrecht; Utrecht the Netherlands
| | - Marco J. Koudijs
- 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
| | | | - Flip Mulder
- Department of Genetics; Center for Molecular Medicine; University Medical Center Utrecht; Utrecht the Netherlands
| | - Ellen C. Carbo
- 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
| | - Nienke E. Verbeek
- 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
| | - Sanne M. C. Savelberg
- 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
| | - 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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43
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Mahdieh N, Mikaeeli S, Badv RS, Shirazi AG, Maleki M, Rabbani B. Pathogenic significance of SCN1A splicing variants causing Dravet syndrome: Improving diagnosis with targeted sequencing for variants by in silico analysis. Clin Neurol Neurosurg 2018; 166:80-90. [PMID: 29408779 DOI: 10.1016/j.clineuro.2018.01.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/21/2018] [Accepted: 01/27/2018] [Indexed: 12/28/2022]
Abstract
OBJECTIVES Genetic heterogeneity of epileptic encephalopathy (IEE) mandates the use of gene-panels for diagnosis. PATIENTS AND METHODS A 36-gene-panel next-generation sequencing was applied for IEE in two Iranian families. A literature search was performed using keywords to identify reported splicing mutations in SCN1A and perform genotype-phenotype correlation. RESULTS An update of splicing mutations revealed 147 variants with 65.75% of them de novo mutations. Most of the familial variants were of parental origin. The structure of the protein was often affected in the linker and transmembrane segments. 92% of intronic variants were pathogenic. A de novo heterozygous mutation was found in the first patient, but not in her sibling and parents. In the second family, a novel de novo heterozygous mutation was found at position c.1210insT leading to a truncated protein. CONCLUSION Gene-panel sequencing is helpful for reducing the time and cost, guiding early treatment, and estimating the recurrence risks. The importance of characterization of intronic variants was noticed; though bioinformatics analysis of novel intronic variants should be of concern for rapid reporting the pathogenic effect of variants.
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Affiliation(s)
- Nejat Mahdieh
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
| | - Sepideh Mikaeeli
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Azadeh Gharehzadeh Shirazi
- Children's Hospital Center, Pediatric Center of Excellence, Tehran University of Medical Center, Tehran, Iran
| | - Majid Maleki
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Bahareh Rabbani
- Genetic Research Laboratory, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
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44
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Fernández-Marmiesse A, Gouveia S, Couce ML. NGS Technologies as a Turning Point in Rare Disease Research , Diagnosis and Treatment. Curr Med Chem 2018; 25:404-432. [PMID: 28721829 PMCID: PMC5815091 DOI: 10.2174/0929867324666170718101946] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Revised: 06/19/2017] [Accepted: 07/14/2017] [Indexed: 01/17/2023]
Abstract
Approximately 25-50 million Americans, 30 million Europeans, and 8% of the Australian population have a rare disease. Rare diseases are thus a common problem for clinicians and account for enormous healthcare costs worldwide due to the difficulty of establishing a specific diagnosis. In this article, we review the milestones achieved in our understanding of rare diseases since the emergence of next-generation sequencing (NGS) technologies and analyze how these advances have influenced research and diagnosis. The first half of this review describes how NGS has changed diagnostic workflows and provided an unprecedented, simple way of discovering novel disease-associated genes. We focus particularly on metabolic and neurodevelopmental disorders. NGS has enabled cheap and rapid genetic diagnosis, highlighted the relevance of mosaic and de novo mutations, brought to light the wide phenotypic spectrum of most genes, detected digenic inheritance or the presence of more than one rare disease in the same patient, and paved the way for promising new therapies. In the second part of the review, we look at the limitations and challenges of NGS, including determination of variant causality, the loss of variants in coding and non-coding regions, and the detection of somatic mosaicism variants and epigenetic mutations, and discuss how these can be overcome in the near future.
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Affiliation(s)
- Ana Fernández-Marmiesse
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain
| | - Sofía Gouveia
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain
| | - María L. Couce
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Pediatrics, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, Spain
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45
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Zhou P, He N, Zhang JW, Lin ZJ, Wang J, Yan LM, Meng H, Tang B, Li BM, Liu XR, Shi YW, Zhai QX, Yi YH, Liao WP. Novel mutations and phenotypes of epilepsy-associated genes in epileptic encephalopathies. GENES BRAIN AND BEHAVIOR 2018; 17:e12456. [PMID: 29314583 DOI: 10.1111/gbb.12456] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/13/2017] [Accepted: 12/30/2017] [Indexed: 12/30/2022]
Abstract
Epileptic encephalopathies are severe epilepsy disorders with strong genetic bases. We performed targeted next-generation sequencing (NGS) in 70 patients with epileptic encephalopathies. The likely pathogenicity of variants in candidate genes was evaluated by American College of Medical Genetics and Genomics (ACMG) scoring taken together with the accepted clinical presentation. Thirty-three candidate variants were detected after population filtration and computational prediction. According to ACMG, 21 candidate variants, including 18 de novo variants, were assessed to be pathogenic/likely pathogenic with clinical concordance. Twelve variants were initially assessed as uncertain significance by ACMG, among which 3 were considered causative and 3 others were considered possibly causative after analysis of clinical concordance. In total, 24 variants were identified as putatively causative, among which 19 were novel findings. SCN1A mutations were identified in 50% of patients with Dravet syndrome. TSC1/TSC2 mutations were detected in 66.7% of patients with tuberous sclerosis. STXBP1 mutations were the main findings in patients with West syndrome. Mutations in SCN2A, KCNT1, KCNQ2 and CLCN4 were identified in patients with epileptic infantile with migrating focal seizures; among them, KCNQ2 and CLCN4 were first identified as potential causative genes. Only one CHD2 mutation was detected in patients with Lennox-Gastaut syndrome. This study highlighted the utility of targeted NGS in genetic diagnoses of epileptic encephalopathies and a comprehensive evaluation of the pathogenicity of variants based on ACMG scoring and assessment of clinical concordance. Epileptic encephalopathies differ in genetic causes, and the genotype-phenotype correlations would provide insights into the underlying pathogenic mechanisms.
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Affiliation(s)
- P Zhou
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - N He
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - J-W Zhang
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Z-J Lin
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - J Wang
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - L-M Yan
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - H Meng
- Department of Neurology, The First Affiliated Hospital of Jinan University, Guangzhou, China.,Clinical Neuroscience Institute, Jinan University, Guangzhou, China
| | - B Tang
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - B-M Li
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - X-R Liu
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Y-W Shi
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - Q-X Zhai
- Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Y-H Yi
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
| | - W-P Liao
- Department of Neurology of the Second Affiliated Hospital of Guangzhou Medical University, Institute of Neuroscience, Guangzhou, China.,Key Laboratory of Neurogenetics, Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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46
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Nakayama T, Ishii A, Yoshida T, Nasu H, Shimojima K, Yamamoto T, Kure S, Hirose S. Somatic mosaic deletions involving SCN1A
cause Dravet syndrome. Am J Med Genet A 2018; 176:657-662. [DOI: 10.1002/ajmg.a.38596] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 10/09/2017] [Accepted: 12/07/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Tojo Nakayama
- Department of Pediatrics; Tohoku University School of Medicine; Sendai Japan
| | - Atsushi Ishii
- Department of Pediatrics; School of Medicine; Fukuoka University; Fukuoka Japan
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy; Fukuoka University; Fukuoka Japan
| | - Takeshi Yoshida
- Department of Pediatrics; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Hirosato Nasu
- National Epilepsy Center; Shizuoka Institute of Epilepsy and Neurological Disorders; Shizuoka Japan
| | - Keiko Shimojima
- Tokyo Women's Medical University Institute for Integrated Medical Sciences; Tokyo Japan
| | - Toshiyuki Yamamoto
- Tokyo Women's Medical University Institute for Integrated Medical Sciences; Tokyo Japan
| | - Shigeo Kure
- Department of Pediatrics; Tohoku University School of Medicine; Sendai Japan
| | - Shinichi Hirose
- Department of Pediatrics; School of Medicine; Fukuoka University; Fukuoka Japan
- Central Research Institute for the Molecular Pathomechanisms of Epilepsy; Fukuoka University; Fukuoka Japan
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47
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Oyrer J, Maljevic S, Scheffer IE, Berkovic SF, Petrou S, Reid CA. Ion Channels in Genetic Epilepsy: From Genes and Mechanisms to Disease-Targeted Therapies. Pharmacol Rev 2018; 70:142-173. [PMID: 29263209 DOI: 10.1124/pr.117.014456] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022] Open
Abstract
Epilepsy is a common and serious neurologic disease with a strong genetic component. Genetic studies have identified an increasing collection of disease-causing genes. The impact of these genetic discoveries is wide reaching-from precise diagnosis and classification of syndromes to the discovery and validation of new drug targets and the development of disease-targeted therapeutic strategies. About 25% of genes identified in epilepsy encode ion channels. Much of our understanding of disease mechanisms comes from work focused on this class of protein. In this study, we review the genetic, molecular, and physiologic evidence supporting the pathogenic role of a number of different voltage- and ligand-activated ion channels in genetic epilepsy. We also review proposed disease mechanisms for each ion channel and highlight targeted therapeutic strategies.
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Affiliation(s)
- Julia Oyrer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Snezana Maljevic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Ingrid E Scheffer
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Samuel F Berkovic
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Steven Petrou
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
| | - Christopher A Reid
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia (J.O., S.M., I.E.S., S.P., C.A.R.); Department of Medicine, Austin Health, University of Melbourne, Heidelberg West, Melbourne, Australia (I.E.S., S.F.B.); and Department of Paediatrics, University of Melbourne, Royal Children's Hospital, Melbourne, Australia (I.E.S.)
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48
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Genomic mosaicism in paternal sperm and multiple parental tissues in a Dravet syndrome cohort. Sci Rep 2017; 7:15677. [PMID: 29142202 PMCID: PMC5688122 DOI: 10.1038/s41598-017-15814-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 11/02/2017] [Indexed: 12/21/2022] Open
Abstract
Genomic mosaicism in parental gametes and peripheral tissues is an important consideration for genetic counseling. We studied a Chinese cohort affected by a severe epileptic disorder, Dravet syndrome (DS). There were 56 fathers who donated semen and 15 parents who donated multiple peripheral tissue samples. We used an ultra-sensitive quantification method, micro-droplet digital PCR (mDDPCR), to detect parental mosaicism of the proband’s pathogenic mutation in SCN1A, the causal gene of DS in 112 families. Ten of the 56 paternal sperm samples were found to exhibit mosaicism of the proband’s mutations, with mutant allelic fractions (MAFs) ranging from 0.03% to 39.04%. MAFs in the mosaic fathers’ sperm were significantly higher than those in their blood (p = 0.00098), even after conditional probability correction (p’ = 0.033). In three mosaic fathers, ultra-low fractions of mosaicism (MAF < 1%) were detected in the sperm samples. In 44 of 45 cases, mosaicism was also observed in other parental peripheral tissues. Hierarchical clustering showed that MAFs measured in the paternal sperm, hair follicles and urine samples were clustered closest together. Milder epileptic phenotypes were more likely to be observed in mosaic parents (p = 3.006e-06). Our study provides new insights for genetic counseling.
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49
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Mantegazza M, Cestèle S. Pathophysiological mechanisms of migraine and epilepsy: Similarities and differences. Neurosci Lett 2017; 667:92-102. [PMID: 29129678 DOI: 10.1016/j.neulet.2017.11.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 11/08/2017] [Accepted: 11/08/2017] [Indexed: 01/03/2023]
Abstract
Migraine and epilepsy are episodic disorders with distinct features, but they have some clinical and pathophysiological overlaps. We review here clinical overlaps between seizures and migraine attacks, activities of neuronal networks observed during seizures and migraine attacks, and molecular and cellular mechanisms of migraine identified in genetic forms, focusing on genetic variants identified in hemiplegic migraine and their functional effects. Epilepsy and migraine can be generated by dysfunctions of the same neuronal networks, but these dysfunctions can be disease-specific, even if pathogenic mutations target the same protein. Studies of rare monogenic forms have allowed the identification of some molecular/cellular dysfunctions that provide a window on pathological mechanisms: we have begun to disclose the tip of the iceberg.
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Affiliation(s)
- Massimo Mantegazza
- Université Côte d'Azur (UCA), 660 route des Lucioles, 06560 Valbonne, Sophia Antipolis, France; Institute of Molecular and Cellular Pharmacology (IPMC), CNRS UMR7275, 660 Route des Lucioles, 06560 Valbonne, Sophia Antipolis, France.
| | - Sandrine Cestèle
- Université Côte d'Azur (UCA), 660 route des Lucioles, 06560 Valbonne, Sophia Antipolis, France; Institute of Molecular and Cellular Pharmacology (IPMC), CNRS UMR7275, 660 Route des Lucioles, 06560 Valbonne, Sophia Antipolis, France
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50
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Losito E, Kuchenbuch M, Chemaly N, Laschet J, Chiron C, Kaminska A, Nabbout R. Age-related "Sleep/nocturnal" tonic and tonic clonic seizure clusters are underdiagnosed in patients with Dravet Syndrome. Epilepsy Behav 2017; 74:33-40. [PMID: 28683344 DOI: 10.1016/j.yebeh.2017.05.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 05/28/2017] [Accepted: 05/28/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVES To describe the semiology and EEG characteristics of the age-related pattern of sleep/nocturnal (S/N) seizures in patients with Dravet Syndrome (DS). METHODS We retrospectively analysed the clinical and EEG data of DS patients followed at our reference centre for Rare Epilepsies. We included patients aged two years and older who fulfilled clinical and EEG criteria of DS (ILAE 1989). Genetic testing for SCN1A was done in all, followed by PCDH19 if this was negative. Patients showing a genetic abnormality in PCDH19 were excluded. Of 73 DS patients followed at our centre, 26 (15 males and 11 females), called the S/N group, experienced a switch in the circadian rhythm of seizures, from mainly awake/diurnal to mainly S/N seizures. We retrospectively analysed their clinical, EEG and genetic data. We have compared them to a second group of 7 patients (4 males and 3 females), aged more than 11years, the non-S/N group, who did not develop S/N seizures. RESULTS We observed a pattern of S/N seizures concomitant with a decrease of awake seizures between 4 and 11years (median 6years 6months). S/N seizures were brief but often occurred in clusters of 2-15 per night. Seizures were mostly focal (26) with frontal-central onset (25) and tonic or tonic-vibratory in semiology. S/N seizure clusters were difficult to control despite many AEDs trials. Benzodiazepines reduced seizure recurrence within a cluster in some patients. While no significant differences were found between groups regarding clinical features, the presence of frontal and central anomalies on wake and sleep EEG was significantly associated with the presence of the S/N pattern. CONCLUSIONS Patients with DS often develop a characteristic clinical and EEG pattern with S/N tonic and tonic clonic seizures that is often underdiagnosed. Seizure semiology and EEG pattern differ from LGS but may worsen the quality of sleep of such patients and their families. The possible role of this pattern in SUDEP occurring mainly during sleep and at the same age should be further explored. Current AEDs have limited efficacy and specific drug trials should be proposed.
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Affiliation(s)
- Emma Losito
- Reference Centre for Rare Epilepsies, APHP, Necker-Enfants Malades Hospital, Imagine institute, Paris, France; INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif sur Yvette, France
| | - Matthieu Kuchenbuch
- Reference Centre for Rare Epilepsies, APHP, Necker-Enfants Malades Hospital, Imagine institute, Paris, France.
| | - Nicole Chemaly
- Reference Centre for Rare Epilepsies, APHP, Necker-Enfants Malades Hospital, Imagine institute, Paris, France; INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif sur Yvette, France.
| | - Jacques Laschet
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif sur Yvette, France.
| | - Catherine Chiron
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif sur Yvette, France.
| | - Anna Kaminska
- INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif sur Yvette, France; Department of Clinical Neurophysiology, APHP, Necker-Enfants Malades Hospital, Paris, France.
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies, APHP, Necker-Enfants Malades Hospital, Imagine institute, Paris, France; INSERM U1129, Paris, France; Paris Descartes University, CEA, Gif sur Yvette, France.
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