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Sekerková G, Kilic S, Cheng YH, Fredrick N, Osmani A, Kim H, Opal P, Martina M. Phenotypical, genotypical and pathological characterization of the moonwalker mouse, a model of ataxia. Neurobiol Dis 2024; 195:106492. [PMID: 38575093 PMCID: PMC11089908 DOI: 10.1016/j.nbd.2024.106492] [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: 11/01/2023] [Revised: 03/13/2024] [Accepted: 04/01/2024] [Indexed: 04/06/2024] Open
Abstract
We performed a comprehensive study of the morphological, functional, and genetic features of moonwalker (MWK) mice, a mouse model of spinocerebellar ataxia caused by a gain of function of the TRPC3 channel. These mice show numerous behavioral symptoms including tremor, altered gait, circling behavior, impaired motor coordination, impaired motor learning and decreased limb strength. Cerebellar pathology is characterized by early and almost complete loss of unipolar brush cells as well as slowly progressive, moderate loss of Purkinje cell (PCs). Structural damage also includes loss of synaptic contacts from parallel fibers, swollen ER structures, and degenerating axons. Interestingly, no obvious correlation was observed between PC loss and severity of the symptoms, as the phenotype stabilizes around 2 months of age, while the cerebellar pathology is progressive. This is probably due to the fact that PC function is severely impaired much earlier than the appearance of PC loss. Indeed, PC firing is already impaired in 3 weeks old mice. An interesting feature of the MWK pathology that still remains to be explained consists in a strong lobule selectivity of the PC loss, which is puzzling considering that TRPC is expressed in every PC. Intriguingly, genetic analysis of MWK cerebella shows, among other alterations, changes in the expression of both apoptosis inducing and resistance factors possibly suggesting that damaged PCs initiate specific cellular pathways that protect them from overt cell loss.
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Affiliation(s)
- Gabriella Sekerková
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
| | - Sumeyra Kilic
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Yen-Hsin Cheng
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Natalie Fredrick
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Anne Osmani
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Haram Kim
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Puneet Opal
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA
| | - Marco Martina
- Department of Neuroscience, Northwestern University, Feinberg School of Medicine, 300 E. Superior, Chicago, IL 60611, USA.
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2
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Witkowski G, Szulczyk B, Nurowska E, Jurek M, Pasierski M, Lipiec A, Charzewska A, Dawidziuk M, Milewski M, Owsiak S, Rola R, Sienkiewicz Jarosz H, Hoffman-Zacharska D. Functional Characteristics of the Nav1.1 p.Arg1596Cys Mutation Associated with Varying Severity of Epilepsy Phenotypes. Int J Mol Sci 2024; 25:1745. [PMID: 38339022 PMCID: PMC10855957 DOI: 10.3390/ijms25031745] [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: 12/29/2023] [Revised: 01/20/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Mutations of the SCN1A gene, which encodes the voltage-dependent Na+ channel's α subunit, are associated with diverse epileptic syndromes ranging in severity, even intra-family, from febrile seizures to epileptic encephalopathy. The underlying cause of this variability is unknown, suggesting the involvement of additional factors. The aim of our study was to describe the properties of mutated channels and investigate genetic causes for clinical syndromes' variability in the family of five SCN1A gene p.Arg1596Cys mutation carriers. The analysis of additional genetic factors influencing SCN1A-associated phenotypes was conducted through exome sequencing (WES). To assess the impact of mutations, we used patch clamp analysis of mutated channels expressed in HEK cells and in vivo neural excitability studies (NESs). In cells expressing the mutant channel, sodium currents were reduced. NESs indicated increased excitability of peripheral motor neurons in mutation carriers. WES showed the absence of non-SCA1 pathogenic variants that could be causative of disease in the family. Variants of uncertain significance in three genes, as potential modifiers of the most severe phenotype, were identified. The p.Arg1596Cys substitution inhibits channel function, affecting steady-state inactivation kinetics. Its clinical manifestations involve not only epileptic symptoms but also increased excitability of peripheral motor fibers. The role of Nav1.1 in excitatory neurons cannot be ruled out as a significant factor of the clinical phenotype.
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Affiliation(s)
- Grzegorz Witkowski
- First Department of Neurology, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland; (S.O.); (H.S.J.)
- Military Institute of Aviation Medicine, Krasinskiego 54/56, 01-755 Warsaw, Poland;
| | - Bartlomiej Szulczyk
- Chair and Department of Pharmacotherapy and Pharmaceutical Care, Faculty of Pharmacy, The Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland; (B.S.); (E.N.); (M.P.)
| | - Ewa Nurowska
- Chair and Department of Pharmacotherapy and Pharmaceutical Care, Faculty of Pharmacy, The Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland; (B.S.); (E.N.); (M.P.)
| | - Marta Jurek
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Michal Pasierski
- Chair and Department of Pharmacotherapy and Pharmaceutical Care, Faculty of Pharmacy, The Medical University of Warsaw, Banacha 1b, 02-097 Warsaw, Poland; (B.S.); (E.N.); (M.P.)
| | - Agata Lipiec
- Clinic of Pediatric Neurology, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland;
| | - Agnieszka Charzewska
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Mateusz Dawidziuk
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Michal Milewski
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
| | - Szymon Owsiak
- First Department of Neurology, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland; (S.O.); (H.S.J.)
| | - Rafal Rola
- Military Institute of Aviation Medicine, Krasinskiego 54/56, 01-755 Warsaw, Poland;
| | - Halina Sienkiewicz Jarosz
- First Department of Neurology, Institute of Psychiatry and Neurology, Sobieskiego 9, 02-957 Warsaw, Poland; (S.O.); (H.S.J.)
| | - Dorota Hoffman-Zacharska
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17a, 01-211 Warsaw, Poland; (M.J.); (A.C.); (M.M.); (D.H.-Z.)
- Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
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3
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Domaradzki J, Walkowiak D. Caring for Children with Dravet Syndrome: Exploring the Daily Challenges of Family Caregivers. CHILDREN (BASEL, SWITZERLAND) 2023; 10:1410. [PMID: 37628409 PMCID: PMC10453293 DOI: 10.3390/children10081410] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023]
Abstract
While Polish studies focus on the symptoms, causes and treatment of people suffering from Dravet syndrome (DS), much less is known about the situation of the family caregivers of DS children. This study was designed to explore the experiences, daily challenges and needs related to caring for DS children. An anonymous self-administered online questionnaire was developed. The survey was completed by 75 family caregivers affiliated with the Association for People with Severe Refractory Epilepsy DRAVET.PL on Facebook. Most caregivers felt burdened by their children's reduced mobility (57.3%), mood swings (57.3%), lack of access to rehabilitation and medicine (56%) and healthcare expenses (50.7%). Caregivers also complained of a lack of time to themselves (76%) and work restrictions resulting from caregiving (72%). They consequently reported experiencing fatigue (84%), a deterioration of mental health (60%) and intimacy problems with their spouse/partner (53.4%). An important source of strain was a prolonged diagnostic odyssey and the constant struggle over the healthcare services for DS children. Since DS caregivers' problems and needs are often overlooked, they may be described as the forgotten people in DS. Healthcare professionals should be educated about the challenges related to caring for DS child, psycho-social status and coping resources of DS caregivers, and should focus on identification, monitoring and supporting caregivers' physical and mental well-being and needs.
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Affiliation(s)
- Jan Domaradzki
- Department of Social Sciences and Humanities, Poznan University of Medical Sciences, 60-806 Poznań, Poland
| | - Dariusz Walkowiak
- Department of Organization and Management in Health Care, Poznan University of Medical Sciences, 60-356 Poznań, Poland;
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The Generation of Human iPSC Lines from Three Individuals with Dravet Syndrome and Characterization of Neural Differentiation Markers in iPSC-Derived Ventral Forebrain Organoid Model. Cells 2023; 12:cells12020339. [PMID: 36672274 PMCID: PMC9856691 DOI: 10.3390/cells12020339] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/02/2023] [Accepted: 01/07/2023] [Indexed: 01/18/2023] Open
Abstract
Dravet syndrome (DRVT) is a rare form of neurodevelopmental disorder with a high risk of sudden unexpected death in epilepsy (SUDEP), caused mainly (>80% cases) by mutations in the SCN1A gene, coding the Nav1.1 protein (alfa-subunit of voltage-sensitive sodium channel). Mutations in SCN1A are linked to heterogenous epileptic phenotypes of various types, severity, and patient prognosis. Here we generated iPSC lines from fibroblasts obtained from three individuals affected with DRVT carrying distinct mutations in the SCN1A gene (nonsense mutation p.Ser1516*, missense mutation p.Arg1596His, and splicing mutation c.2589+2dupT). The iPSC lines, generated with the non-integrative approach, retained the distinct SCN1A gene mutation of the donor fibroblasts and were characterized by confirming the expression of the pluripotency markers, the three-germ layer differentiation potential, the absence of exogenous vector expression, and a normal karyotype. The generated iPSC lines were used to establish ventral forebrain organoids, the most affected type of neurons in the pathology of DRVT. The DRVT organoid model will provide an additional resource for deciphering the pathology behind Nav1.1 haploinsufficiency and drug screening to remediate the functional deficits associated with the disease.
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Concise Review: Stem Cell Models of SCN1A-Related Encephalopathies—Current Perspective and Future Therapies. Cells 2022; 11:cells11193119. [PMID: 36231081 PMCID: PMC9561991 DOI: 10.3390/cells11193119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 11/17/2022] Open
Abstract
Mutations in the SCN1A gene can cause a variety of phenotypes, ranging from mild forms, such as febrile seizures and generalized epilepsy with febrile seizures plus, to severe, such as Dravet and non-Dravet developmental epileptic encephalopathies. Until now, more than two thousand pathogenic variants of the SCN1A gene have been identified and different pathogenic mechanisms (loss vs. gain of function) described, but the precise molecular mechanisms responsible for the deficits exhibited by patients are not fully elucidated. Additionally, the phenotypic variability proves the involvement of other genetic factors in its final expression. This is the reason why animal models and cell line models used to explore the molecular pathology of SCN1A-related disorders are only of limited use. The results of studies based on such models cannot be directly translated to affected individuals because they do not address each patient’s unique genetic background. The generation of functional neurons and glia for patient-derived iPSCs, together with the generation of isogenic controls using CRISPR/Cas technology, and finally, the 3D brain organoid models, seem to be a good way to solve this problem. Here, we review SCN1A-related encephalopathies, as well as the stem cell models used to explore their molecular basis.
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6
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Genetic therapeutic advancements for Dravet Syndrome. Epilepsy Behav 2022; 132:108741. [PMID: 35653814 DOI: 10.1016/j.yebeh.2022.108741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/05/2022] [Accepted: 05/11/2022] [Indexed: 11/03/2022]
Abstract
Dravet Syndrome is a genetic epileptic syndrome characterized by severe and intractable seizures associated with cognitive, motor, and behavioral impairments. The disease is also linked with increased mortality mainly due to sudden unexpected death in epilepsy. Over 80% of cases are due to a de novo mutation in one allele of the SCN1A gene, which encodes the α-subunit of the voltage-gated ion channel NaV1.1. Dravet Syndrome is usually refractory to antiepileptic drugs, which only alleviate seizures to a small extent. Viral, non-viral genetic therapy, and gene editing tools are rapidly enhancing and providing new platforms for more effective, alternative medicinal treatments for Dravet syndrome. These strategies include gene supplementation, CRISPR-mediated transcriptional activation, and the use of antisense oligonucleotides. In this review, we summarize our current knowledge of novel genetic therapies that are currently under development for Dravet syndrome.
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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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8
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Menezes LFS, Sabiá Júnior EF, Tibery DV, Carneiro LDA, Schwartz EF. Epilepsy-Related Voltage-Gated Sodium Channelopathies: A Review. Front Pharmacol 2020; 11:1276. [PMID: 33013363 PMCID: PMC7461817 DOI: 10.3389/fphar.2020.01276] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/31/2020] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a disease characterized by abnormal brain activity and a predisposition to generate epileptic seizures, leading to neurobiological, cognitive, psychological, social, and economic impacts for the patient. There are several known causes for epilepsy; one of them is the malfunction of ion channels, resulting from mutations. Voltage-gated sodium channels (NaV) play an essential role in the generation and propagation of action potential, and malfunction caused by mutations can induce irregular neuronal activity. That said, several genetic variations in NaV channels have been described and associated with epilepsy. These mutations can affect channel kinetics, modifying channel activation, inactivation, recovery from inactivation, and/or the current window. Among the NaV subtypes related to epilepsy, NaV1.1 is doubtless the most relevant, with more than 1500 mutations described. Truncation and missense mutations are the most observed alterations. In addition, several studies have already related mutated NaV channels with the electrophysiological functioning of the channel, aiming to correlate with the epilepsy phenotype. The present review provides an overview of studies on epilepsy-associated mutated human NaV1.1, NaV1.2, NaV1.3, NaV1.6, and NaV1.7.
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Affiliation(s)
- Luis Felipe Santos Menezes
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Elias Ferreira Sabiá Júnior
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Diogo Vieira Tibery
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
| | - Lilian Dos Anjos Carneiro
- Faculdade de Medicina, Centro Universitário Euro Americano, Brasília, Brazil.,Faculdade de Medicina, Centro Universitário do Planalto Central, Brasília, Brazil
| | - Elisabeth Ferroni Schwartz
- Laboratório de Neurofarmacologia, Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, Brazil
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9
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Kluckova D, Kolnikova M, Lacinova L, Jurkovicova-Tarabova B, Foltan T, Demko V, Kadasi L, Ficek A, Soltysova A. A Study among the Genotype, Functional Alternations, and Phenotype of 9 SCN1A Mutations in Epilepsy Patients. Sci Rep 2020; 10:10288. [PMID: 32581296 PMCID: PMC7314844 DOI: 10.1038/s41598-020-67215-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/26/2020] [Indexed: 12/14/2022] Open
Abstract
Mutations in the voltage-gated sodium channel Nav1.1 (SCN1A) are linked to various epileptic phenotypes with different severities, however, the consequences of newly identified SCN1A variants on patient phenotype is uncertain so far. The functional impact of nine SCN1A variants, including five novel variants identified in this study, was studied using whole-cell patch-clamp recordings measurement of mutant Nav1.1 channels expressed in HEK293T mammalian cells. E78X, W384X, E1587K, and R1596C channels failed to produce measurable sodium currents, indicating complete loss of channel function. E788K and M909K variants resulted in partial loss of function by exhibiting reduced current density, depolarizing shifts of the activation and hyperpolarizing shifts of the inactivation curves, and slower recovery from inactivation. Hyperpolarizing shifts of the activation and inactivation curves were observed in D249E channels along with slower recovery from inactivation. Slower recovery from inactivation was observed in E78D and T1934I with reduced current density in T1934I channels. Various functional effects were observed with the lack of sodium current being mainly associated with severe phenotypes and milder symptoms with less damaging channel alteration. In vitro functional analysis is thus fundamental for elucidation of the molecular mechanisms of epilepsy, to guide patients' treatment, and finally indicate misdiagnosis of SCN1A related epilepsies.
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Affiliation(s)
- Daniela Kluckova
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Miriam Kolnikova
- Department of Pediatric Neurology, Comenius University Medical School and National Institute of Children's Diseases, Limbova 1, Bratislava, 833 40, Slovakia
| | - Lubica Lacinova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravská cesta 9, Bratislava, 840 05, Slovakia
| | - Bohumila Jurkovicova-Tarabova
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Dubravská cesta 9, Bratislava, 840 05, Slovakia
| | - Tomas Foltan
- Department of Pediatric Neurology, Comenius University Medical School and National Institute of Children's Diseases, Limbova 1, Bratislava, 833 40, Slovakia
| | - Viktor Demko
- Department of Plant Physiology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Ludevit Kadasi
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia.,Institute for Clinical and Translational Research, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05, Bratislava, Slovakia
| | - Andrej Ficek
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia
| | - Andrea Soltysova
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, Bratislava, 842 15, Slovakia. .,Institute for Clinical and Translational Research, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, 845 05, Bratislava, Slovakia.
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10
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Whole exome sequencing identifies a novel SCN1A mutation in genetic (idiopathic) generalized epilepsy and juvenile myoclonic epilepsy subtypes. Neurol Sci 2019; 41:591-598. [DOI: 10.1007/s10072-019-04122-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 10/22/2019] [Indexed: 12/30/2022]
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11
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Helbig I, Riggs ER, Barry CA, Klein KM, Dyment D, Thaxton C, Sadikovic B, Sands TT, Wagnon JL, Liaquat K, Cilio MR, Mirzaa G, Park K, Axeen E, Butler E, Bardakjian TM, Striano P, Poduri A, Siegert RK, Grant AR, Helbig KL, Mefford HC. The ClinGen Epilepsy Gene Curation Expert Panel-Bridging the divide between clinical domain knowledge and formal gene curation criteria. Hum Mutat 2019; 39:1476-1484. [PMID: 30311377 DOI: 10.1002/humu.23632] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 08/01/2018] [Accepted: 08/28/2018] [Indexed: 01/03/2023]
Abstract
The field of epilepsy genetics is advancing rapidly and epilepsy is emerging as a frequent indication for diagnostic genetic testing. Within the larger ClinGen framework, the ClinGen Epilepsy Gene Curation Expert Panel is tasked with connecting two increasingly separate fields: the domain of traditional clinical epileptology, with its own established language and classification criteria, and the rapidly evolving area of diagnostic genetic testing that adheres to formal criteria for gene and variant curation. We identify critical components unique to the epilepsy gene curation effort, including: (a) precise phenotype definitions within existing disease and phenotype ontologies; (b) consideration of when epilepsy should be curated as a distinct disease entity; (c) strategies for gene selection; and (d) emerging rules for evaluating functional models for seizure disorders. Given that de novo variants play a prominent role in many of the epilepsies, sufficient genetic evidence is often awarded early in the curation process. Therefore, the emphasis of gene curation is frequently shifted toward an iterative precuration process to better capture phenotypic associations. We demonstrate that within the spectrum of neurodevelopmental disorders, gene curation for epilepsy-associated genes is feasible and suggest epilepsy-specific conventions, laying the groundwork for a curation process of all major epilepsy-associated genes.
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Affiliation(s)
- Ingo Helbig
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Neuropediatrics, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Erin Rooney Riggs
- Autism & Developmental Medicine Institute, Geisinger Health System, Lewisburg, Pennsylvania, USA
| | - Carrie-Anne Barry
- Autism & Developmental Medicine Institute, Geisinger Health System, Lewisburg, Pennsylvania, USA
| | - Karl Martin Klein
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Goethe University, Frankfurt am Main, Frankfurt, Germany.,Department of Neurology, Epilepsy Center Hessen, Philipps University, Marburg, Marburg, Germany
| | - David Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada
| | - Courtney Thaxton
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Bekim Sadikovic
- Department of Pathology and Laboratory Medicine, Western University Molecular Genetic Laboratory, London Health Sciences, London, Ontario, Canada
| | - Tristan T Sands
- Division of Child Neurology, Columbia University Medical Center, New York, New York, USA
| | - Jacy L Wagnon
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Khalida Liaquat
- Quest Diagnostics, Athena Diagnostics, Marlborough, Massachusetts, USA
| | - Maria Roberta Cilio
- Departments of Pediatrics and Neurology, University of California, San Francisco, California, USA
| | - Ghayda Mirzaa
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA.,Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Kristen Park
- Department of Pediatrics and Neurology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Erika Axeen
- Department of Neurology, University of Virginia, Charlottesville, Virginia, USA
| | | | - Tanya M Bardakjian
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, DINOGMI-Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| | - Annapurna Poduri
- Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Rebecca K Siegert
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts, USA
| | - Andrew R Grant
- Laboratory for Molecular Medicine, Partners Healthcare Personalized Medicine, Cambridge, Massachusetts, USA
| | - Katherine L Helbig
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Heather C Mefford
- Division of Genetic Medicine, University of Washington, Seattle, Washington, USA
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Kivity S, Oliver KL, Afawi Z, Damiano JA, Arsov T, Bahlo M, Berkovic SF. SCN1A clinical spectrum includes the self-limited focal epilepsies of childhood. Epilepsy Res 2017; 131:9-14. [PMID: 28192756 DOI: 10.1016/j.eplepsyres.2017.01.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/18/2017] [Accepted: 01/28/2017] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Amongst autosomal dominant genetic epilepsy with febrile seizures plus (GEFS+) families, SCN1A variants are the most common genetic cause. Initially regarded as a generalized form of epilepsy, the GEFS+ spectrum is now known to include some focal epilepsies, but it is generally not conceptualized as extending to the self-limited focal epilepsies of childhood, such as Panayiotopoulos syndrome. There are, however, three reports of SCN1A variants in Panayiotopoulos syndrome. We describe the variable clinical phenotypes that include the self-limited focal epilepsies of childhood, present in a large GEFS+ family, segregating a heterozygous SCN1A missense variant. MATERIAL AND METHODS Electro-clinical details on all putatively affected family members were sought and blood samples were taken for genetic analysis. Two individuals were chosen for SCN1A testing. All 26 exons and exon-intron junctions were amplified, sequenced and analyzed. This was followed by pedigree segregation analysis of the variant identified. RESULTS A pathogenic heterozygous SCN1A (c.2624C>A; p.Thr875Lys) variant was identified. Sixteen of the 18 variant positive family members were affected (88% penetrance): 8 with febrile seizures, 2 febrile seizures plus, 1 unclassified seizures and 5 with self-limited focal epilepsy of childhood. Of these, one was diagnosed with atypical childhood epilepsy with centrotemporal spikes and four with Panayiotopoulos syndrome. DISCUSSION By characterizing the heterogeneous clinical phenotypes in a large, SCN1A mutation positive GEFS+ family, we conclude that the GEFS+ spectrum can extend to the self-limited focal epilepsies of childhood, including Panayiotopoulos syndrome, and in turn highlight the complex genotype-phenotype correlations associated with SCN1A-related epilepsies.
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Affiliation(s)
- Sara Kivity
- Epilepsy Unit, Schneider Children's Medical Center of Israel, Petah Tiqvah, Israel
| | - Karen L Oliver
- Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg, Australia
| | - Zaid Afawi
- Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Israel
| | - John A Damiano
- Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg, Australia
| | - Todor Arsov
- Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Samuel F Berkovic
- Epilepsy Research Centre, University of Melbourne, Austin Health, Heidelberg, Australia.
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Møller RS, Larsen LHG, Johannesen KM, Talvik I, Talvik T, Vaher U, Miranda MJ, Farooq M, Nielsen JEK, Svendsen LL, Kjelgaard DB, Linnet KM, Hao Q, Uldall P, Frangu M, Tommerup N, Baig SM, Abdullah U, Born AP, Gellert P, Nikanorova M, Olofsson K, Jepsen B, Marjanovic D, Al-Zehhawi LIK, Peñalva SJ, Krag-Olsen B, Brusgaard K, Hjalgrim H, Rubboli G, Pal DK, Dahl HA. Gene Panel Testing in Epileptic Encephalopathies and Familial Epilepsies. Mol Syndromol 2016; 7:210-219. [PMID: 27781031 DOI: 10.1159/000448369] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In recent years, several genes have been causally associated with epilepsy. However, making a genetic diagnosis in a patient can still be difficult, since extensive phenotypic and genetic heterogeneity has been observed in many monogenic epilepsies. This study aimed to analyze the genetic basis of a wide spectrum of epilepsies with age of onset spanning from the neonatal period to adulthood. A gene panel targeting 46 epilepsy genes was used on a cohort of 216 patients consecutively referred for panel testing. The patients had a range of different epilepsies from benign neonatal seizures to epileptic encephalopathies (EEs). Potentially causative variants were evaluated by literature and database searches, submitted to bioinformatic prediction algorithms, and validated by Sanger sequencing. If possible, parents were included for segregation analysis. We identified a presumed disease-causing variant in 49 (23%) of the 216 patients. The variants were found in 19 different genes including SCN1A, STXBP1, CDKL5, SCN2A, SCN8A, GABRA1, KCNA2, and STX1B. Patients with neonatal-onset epilepsies had the highest rate of positive findings (57%). The overall yield for patients with EEs was 32%, compared to 17% among patients with generalized epilepsies and 16% in patients with focal or multifocal epilepsies. By the use of a gene panel consisting of 46 epilepsy genes, we were able to find a disease-causing genetic variation in 23% of the analyzed patients. The highest yield was found among patients with neonatal-onset epilepsies and EEs.
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Affiliation(s)
- Rikke S Møller
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | | | - Katrine M Johannesen
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | - Inga Talvik
- Tallinn Children's Hospital, Tallinn, Estonia; Tartu University Hospital, Children's Clinic, Tartu, Estonia
| | - Tiina Talvik
- Tartu University Hospital, Children's Clinic, Tartu, Estonia; Department of Paediatrics, University of Tartu, Tartu, Estonia
| | - Ulvi Vaher
- Tartu University Hospital, Children's Clinic, Tartu, Estonia; Department of Paediatrics, University of Tartu, Tartu, Estonia
| | - Maria J Miranda
- Department of Pediatrics, Pediatric Neurology, Herlev University Hospital, Copenhagen University, Herlev, Denmark
| | - Muhammad Farooq
- Department of Cellular and Molecular Medicine, Wilhelm Johannsen Centre for Functional Genome Research, University of Copenhagen, Copenhagen, Denmark; Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE)-PIEAS, Faisalabad, Pakistan
| | - Jens E K Nielsen
- Department of Clinical Medicine, Section of Gynaecology, Obstetrics and Paediatrics, Roskilde Hospital, Roskilde, Denmark
| | | | | | - Karen M Linnet
- Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
| | - Qin Hao
- Amplexa Genetics, Odense, Denmark
| | - Peter Uldall
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | - Mimoza Frangu
- Department of Pediatrics, Holbæk Hospital, Holbæk, Denmark
| | - Niels Tommerup
- Department of Cellular and Molecular Medicine, Wilhelm Johannsen Centre for Functional Genome Research, University of Copenhagen, Copenhagen, Denmark
| | - Shahid M Baig
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE)-PIEAS, Faisalabad, Pakistan
| | - Uzma Abdullah
- Department of Cellular and Molecular Medicine, Wilhelm Johannsen Centre for Functional Genome Research, University of Copenhagen, Copenhagen, Denmark; Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE)-PIEAS, Faisalabad, Pakistan
| | - Alfred P Born
- Department of Paediatrics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Pia Gellert
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | - Marina Nikanorova
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | - Kern Olofsson
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | - Birgit Jepsen
- Danish Epilepsy Centre, University of Southern Denmark, Denmark
| | | | - Lana I K Al-Zehhawi
- Department of Clinical Genetics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Bente Krag-Olsen
- Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Helle Hjalgrim
- Danish Epilepsy Centre, University of Southern Denmark, Denmark; Institute for Regional Health Services, University of Southern Denmark, Denmark
| | - Guido Rubboli
- Danish Epilepsy Centre, Filadelfia, Dianalund, Denmark
| | - Deb K Pal
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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