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Sullivan J, Benítez A, Roth J, Andrews JS, Shah D, Butcher E, Jones A, Cross JH. A systematic literature review on the global epidemiology of Dravet syndrome and Lennox-Gastaut syndrome: Prevalence, incidence, diagnosis, and mortality. Epilepsia 2024; 65:1240-1263. [PMID: 38252068 DOI: 10.1111/epi.17866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/14/2023] [Accepted: 12/14/2023] [Indexed: 01/23/2024]
Abstract
Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare developmental and epileptic encephalopathies associated with seizure and nonseizure symptoms. A comprehensive understanding of how many individuals are affected globally, the diagnostic journey they face, and the extent of mortality associated with these conditions is lacking. Here, we summarize and evaluate published data on the epidemiology of DS and LGS in terms of prevalence, incidence, diagnosis, genetic mutations, and mortality and sudden unexpected death in epilepsy (SUDEP) rates. The full study protocol is registered on PROSPERO (CRD42022316930). After screening 2172 deduplicated records, 91 unique records were included; 67 provided data on DS only, 17 provided data on LGS only, and seven provided data on both. Case definitions varied considerably across studies, particularly for LGS. Incidence and prevalence estimates per 100 000 individuals were generally higher for LGS than for DS (LGS: incidence proportion = 14.5-28, prevalence = 5.8-60.8; DS: incidence proportion = 2.2-6.5, prevalence = 1.2-6.5). Diagnostic delay was frequently reported for LGS, with a wider age range at diagnosis reported than for DS (DS, 1.6-9.2 years; LGS, 2-15 years). Genetic screening data were reported by 63 studies; all screened for SCN1A variants, and only one study specifically focused on individuals with LGS. Individuals with DS had a higher mortality estimate per 1000 person-years than individuals with LGS (DS, 15.84; LGS, 6.12) and a lower median age at death. SUDEP was the most frequently reported cause of death for individuals with DS. Only four studies reported mortality information for LGS, none of which included SUDEP. This systematic review highlights the paucity of epidemiological data available for DS and especially LGS, demonstrating the need for further research and adoption of standardized diagnostic criteria.
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Affiliation(s)
- Joseph Sullivan
- Department of Neurology, University of California, San Francisco, San Francisco, California, USA
| | - Arturo Benítez
- Takeda Development Center Americas, Cambridge, Massachusetts, USA
| | - Jeannine Roth
- Takeda Pharmaceuticals International, Zurich, Switzerland
| | - J Scott Andrews
- Takeda Development Center Americas, Cambridge, Massachusetts, USA
| | - Drishti Shah
- Takeda Development Center Americas, Cambridge, Massachusetts, USA
| | | | | | - J Helen Cross
- University College London, National Institute for Health and Care Research Biomedical Research Centre, London, UK
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Wang JY, Tang B, Sheng WX, Hua LD, Zeng Y, Fan CX, Deng WY, Gao MM, Zhu WW, He N, Su T. Clinical and Functional Features of Epilepsy-Associated In-Frame Deletion Variants in SCN1A. Front Mol Neurosci 2022; 15:828846. [PMID: 35359575 PMCID: PMC8964123 DOI: 10.3389/fnmol.2022.828846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Objective Naturally occurring in-frame deletion is a unique type of genetic variations, causing the loss of one or more amino acids of proteins. A number of in-frame deletion variants in an epilepsy-associated gene SCN1A, encoding voltage gated sodium channel alpha unit 1.1 (Nav1.1), have been reported in public database. In contrast to the missense and truncation variants, the in-frame deletions in SCN1A remains largely uncharacterized. Methods We summarized the basic information of forty-four SCN1A in-frame deletion variants and performed further analysis on six variants identified in our cases with epilepsy. Mutants of the six in-frame deletions and one truncating variant used as comparison were generated and co-transfected with beta-1 and -2 subunits in tsA201 cells, followed by patch clamp recordings. Results Reviewing all the in-frame deletions showed that they spread over the entire Nav1.1 protein, without obvious “hot spots.” The dominant type (54%) was single residue loss. There was no obvious relationship between the length or locations of deletions and their clinical phenotypes. The six in-frame deletions were two single residue deletions (p.M400del and p.I1772del), one microdeletion (p.S128_F130del) and three macrodeletions (p.T303_R322del, p.T160_Y202del, and p.V1335_V1428del). They scatter and affect different functional domains, including transmembrane helices, pore region, and P-loop. Electrophysiological recordings revealed no measurable sodium current in all of the six mutants. In contrast, the truncating mutant p.M1619Ifs*7 that loses a long stretch of peptides retains partial function. Significance The complete loss-of-function in these shortened, abnormal mutants indicates that Nav1.1 protein is a highly accurate structure, and many of the residues have no redundancy to ion conductance. In-frame deletions caused particularly deleterious effect on protein function possibly due to the disruption of ordered residues.
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Affiliation(s)
- Jing-Yang Wang
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
- Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Bin Tang
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Wen-Xiang Sheng
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Li-Dong Hua
- Translational Medicine Center, Maternal and Child Health Research Institute, Guangdong Women and Children’s Hospital, Guangzhou, China
| | - Yang Zeng
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Cui-Xia Fan
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Wei-Yi Deng
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Mei-Mei Gao
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
| | - Wei-Wen Zhu
- Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Na He
- Department of Neurology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Tao Su
- Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Key Laboratory of Neurogenetics and Channelopathies, Ministry of Education of China, Guangzhou, China
- *Correspondence: Tao Su,
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Ding J, Wang L, Jin Z, Qiang Y, Li W, Wang Y, Zhu C, Jiang S, Xiao L, Hao X, Hu X, Li X, Wang F, Sun T. Do All Roads Lead to Rome? Genes Causing Dravet Syndrome and Dravet Syndrome-Like Phenotypes. Front Neurol 2022; 13:832380. [PMID: 35359639 PMCID: PMC8961694 DOI: 10.3389/fneur.2022.832380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/26/2022] [Indexed: 11/16/2022] Open
Abstract
Background Dravet syndrome (DS) is a severe epileptic encephalopathy mainly caused by haploinsufficiency of the gene SCN1A, which encodes the voltage-gated sodium channel NaV1. 1 in the brain. While SCN1A mutations are known to be the primary cause of DS, other genes that may cause DS are poorly understood. Several genes with pathogenic mutations result in DS or DS-like phenotypes, which may require different drug treatment approaches. Therefore, it is urgent for clinicians, especially epilepsy specialists to fully understand these genes involved in DS in addition to SCN1A. Particularly for healthcare providers, a deep understanding of these pathogenic genes is useful in properly selecting and adjusting drugs in a more effective and timely manner. Objective The purpose of this study was to identify genes other than SCN1A that may also cause DS or DS-like phenotypes. Methods A comprehensive search of relevant Dravet syndrome and severe myoclonic epilepsy in infancy was performed in PubMed, until December 1, 2021. Two independent authors performed the screening for potentially eligible studies. Disagreements were decided by a third, more professional researcher or by all three. The results reported by each study were narratively summarized. Results A PubMed search yielded 5,064 items, and other sources search 12 records. A total of 29 studies published between 2009 and 2021 met the inclusion criteria. Regarding the included articles, seven studies on PCDH19, three on SCN2A, two on SCN8A, five on SCN1B, two on GABRA1, three on GABRB3, three on GABRG2, and three on STXBP1 were included. Only one study was recorded for CHD2, CPLX1, HCN1 and KCNA2, respectively. It is worth noting that a few articles reported on more than one epilepsy gene. Conclusion DS is not only identified in variants of SCN1A, but other genes such as PCDH19, SCN2A, SCN8A, SCN1B, GABRA1, GABRB3, GABRG2, KCNA2, CHD2, CPLX1, HCN1A, STXBP1 can also be involved in DS or DS-like phenotypes. As genetic testing becomes more widely available, more genes associated with DS and DS-like phenotypes may be identified and gene-based diagnosis of subtypes of phenotypes in this spectrum may improve the management of these diseases in the future.
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Affiliation(s)
- Jiangwei Ding
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Lei Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Zhe Jin
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Yuanyuan Qiang
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Wenchao Li
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Yangyang Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Changliang Zhu
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Shucai Jiang
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Lifei Xiao
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Xiaoyan Hao
- Department of Neurology, First Affiliated Hospital of Zhengzhou Universiy, Zhengzhou, China
| | - Xulei Hu
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Xinxiao Li
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Xinxiao Li
| | - Feng Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Feng Wang
| | - Tao Sun
- Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
- *Correspondence: Tao Sun
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Ding J, Li X, Tian H, Wang L, Guo B, Wang Y, Li W, Wang F, Sun T. SCN1A Mutation-Beyond Dravet Syndrome: A Systematic Review and Narrative Synthesis. Front Neurol 2022; 12:743726. [PMID: 35002916 PMCID: PMC8739186 DOI: 10.3389/fneur.2021.743726] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/29/2021] [Indexed: 12/28/2022] Open
Abstract
Background:SCN1A is one of the most common epilepsy genes. About 80% of SCN1A gene mutations cause Dravet syndrome (DS), which is a severe and catastrophic epileptic encephalopathy. More than 1,800 mutations have been identified in SCN1A. Although it is known that SCN1A is the main cause of DS and genetic epilepsy with febrile seizures plus (GEFS+), there is a dearth of information on the other related diseases caused by mutations of SCN1A. Objective: The aim of this study is to systematically review the literature associated with SCN1A and other non-DS-related disorders. Methods: We searched PubMed and SCOPUS for all the published cases related to gene mutations of SCN1A until October 20, 2021. The results reported by each study were summarized narratively. Results: The PubMed and SCOPUS search yielded 2,889 items. A total of 453 studies published between 2005 and 2020 met the final inclusion criteria. Overall, 303 studies on DS, 93 on GEFS+, three on Doose syndrome, nine on the epilepsy of infancy with migrating focal seizures (EIMFS), six on the West syndrome, two on the Lennox–Gastaut syndrome (LGS), one on the Rett syndrome, seven on the nonsyndromic epileptic encephalopathy (NEE), 19 on hemiplegia migraine, six on autism spectrum disorder (ASD), two on nonepileptic SCN1A-related sudden deaths, and two on the arthrogryposis multiplex congenital were included. Conclusion: Aside from DS, SCN1A also causes other epileptic encephalopathies, such as GEFS+, Doose syndrome, EIMFS, West syndrome, LGS, Rett syndrome, and NEE. In addition to epilepsy, hemiplegic migraine, ASD, sudden death, and arthrogryposis multiplex congenital can also be caused by mutations of SCN1A.
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Affiliation(s)
- Jiangwei Ding
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Xinxiao Li
- Department of Neurosurgery, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Haiyan Tian
- Department of Neurology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Lei Wang
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Baorui Guo
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Yangyang Wang
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Wenchao Li
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Feng Wang
- Department of Neurosurgery, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Tao Sun
- Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Ningxia Key Laboratory of Cerebrocranial Disease, The Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
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5
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Anvekar P, Lohana P, Elmahal M, Ali SR. The Curious Case of Lennox-Gastaut Syndrome: Treatment-Resistant Seizures in a Patient With Autism Spectrum Disease With Lennox-Gastaut Syndrome. Cureus 2021; 13:e16784. [PMID: 34513391 PMCID: PMC8405377 DOI: 10.7759/cureus.16784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2021] [Indexed: 11/17/2022] Open
Abstract
Lennox-Gastaut syndrome (LGS) is a childhood epilepsy disorder seen between the ages of one to eight years with the electroencephalogram (EEG) changes showing slow spiked-wave complex bursts or paroxysms of generalized fast activity and intellectual disability and often needing multiple lines of treatment. Autism spectrum disease (ASD) is rare but catastrophic comorbidity seen in a patient with LGS. We report an eight-year-old boy presenting to the emergency department with seizures and mental retardation. His first seizure was at the age of five months but was symptomatically treated without any specific diagnosis. On further investigation, the patient was diagnosed with LGS with concomitant ASD. The patient has successfully been treated for his treatment-resistant seizures and is now on regular follow-ups. This article aims to highlight this rare combination of LGS along with ASD and understand the disease course.
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Affiliation(s)
- Priyanka Anvekar
- Internal Medicine, Mahatma Gandhi Mission (MGM) Medical College and Hospital, Mumbai, IND
| | - Petras Lohana
- Internal Medicine, Liaquat University of Medical and Health Sciences Hospital, Karachi, PAK
| | | | - Syed R Ali
- Internal Medicine, Civil Hospital, Dow University of Health Sciences, Karachi, PAK
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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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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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8
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Perry CJ, Finch P, Müller‐Taubenberger A, Leung K, Warren EC, Damstra‐Oddy J, Sharma D, Patra PH, Glyn S, Boberska J, Stewart B, Baldwin A, Piscitelli F, Harvey RJ, Harwood A, Thompson C, Claus SP, Greene ND, McNeish AJ, Williams CM, Whalley BJ, Williams RS. A new mechanism for cannabidiol in regulating the one-carbon cycle and methionine levels in Dictyostelium and in mammalian epilepsy models. Br J Pharmacol 2020; 177:912-928. [PMID: 31693171 PMCID: PMC7024701 DOI: 10.1111/bph.14892] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 09/06/2019] [Accepted: 09/17/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Epidiolex™, a form of highly purified cannabidiol (CBD) derived from Cannabis plants, has demonstrated seizure control activity in patients with Dravet syndrome, without a fully elucidated mechanism of action. We have employed an unbiased approach to investigate this mechanism at a cellular level. EXPERIMENTAL APPROACH We use a tractable biomedical model organism, Dictyostelium, to identify a protein controlling the effect of CBD and characterize this mechanism. We then translate these results to a Dravet syndrome mouse model and an acute in vitro seizure model. KEY RESULTS CBD activity is partially dependent upon the mitochondrial glycine cleavage system component, GcvH1 in Dictyostelium, orthologous to the human glycine cleavage system component H protein, which is functionally linked to folate one-carbon metabolism (FOCM). Analysis of FOCM components identified a mechanism for CBD in directly inhibiting methionine synthesis. Analysis of brain tissue from a Dravet syndrome mouse model also showed drastically altered levels of one-carbon components including methionine, and an in vitro rat seizure model showed an elevated level of methionine that is attenuated following CBD treatment. CONCLUSIONS AND IMPLICATIONS Our results suggest a novel mechanism for CBD in the regulating methionine levels and identify altered one-carbon metabolism in Dravet syndrome and seizure activity.
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Affiliation(s)
- Christopher J. Perry
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Paul Finch
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | | | - Kit‐Yi Leung
- Development Biology and Cancer ProgramUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Eleanor C. Warren
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Joseph Damstra‐Oddy
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Devdutt Sharma
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
| | - Pabitra H. Patra
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Sarah Glyn
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Joanna Boberska
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Balint Stewart
- Faculty of Life SciencesManchester UniversityManchesterUK
| | - Amy Baldwin
- Neuroscience and Mental Health Research InstituteCardiff UniversityCardiffUK
| | - Fabiana Piscitelli
- Institute of Biomolecular ChemistryConsiglio Nazionale delle RicercheRomeItaly
| | - Robert J. Harvey
- School of Health and Sport SciencesUniversity of the Sunshine CoastSippy DownsQLDAustralia
- Sunshine Coast Health InstituteUniversity of the Sunshine CoastBirtinyaQLDAustralia
| | - Adrian Harwood
- Neuroscience and Mental Health Research InstituteCardiff UniversityCardiffUK
| | | | - Sandrine P. Claus
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Nicholas D.E. Greene
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Alister J. McNeish
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Claire M. Williams
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Benjamin J. Whalley
- The School of Chemistry, Food Biosciences and PharmacyUniversity of ReadingReadingUK
| | - Robin S.B. Williams
- Centre for Biomedical Sciences, Department of Biological SciencesRoyal Holloway University of LondonEghamUK
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9
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Ali Rodriguez R, Joya C, Hines RM. Common Ribs of Inhibitory Synaptic Dysfunction in the Umbrella of Neurodevelopmental Disorders. Front Mol Neurosci 2018; 11:132. [PMID: 29740280 PMCID: PMC5928253 DOI: 10.3389/fnmol.2018.00132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/03/2018] [Indexed: 01/06/2023] Open
Abstract
The term neurodevelopmental disorder (NDD) is an umbrella term used to group together a heterogeneous class of disorders characterized by disruption in cognition, emotion, and behavior, early in the developmental timescale. These disorders are heterogeneous, yet they share common behavioral symptomatology as well as overlapping genetic contributors, including proteins involved in the formation, specialization, and function of synaptic connections. Advances may arise from bridging the current knowledge on synapse related factors indicated from both human studies in NDD populations, and in animal models. Mounting evidence has shown a link to inhibitory synapse formation, specialization, and function among Autism, Angelman, Rett and Dravet syndromes. Inhibitory signaling is diverse, with numerous subtypes of inhibitory interneurons, phasic and tonic modes of inhibition, and the molecular and subcellular diversity of GABAA receptors. We discuss common ribs of inhibitory synapse dysfunction in the umbrella of NDD, highlighting alterations in the developmental switch to inhibitory GABA, dysregulation of neuronal activity patterns by parvalbumin-positive interneurons, and impaired tonic inhibition. Increasing our basic understanding of inhibitory synapses, and their role in NDDs is likely to produce significant therapeutic advances in behavioral symptom alleviation for interrelated NDDs.
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Affiliation(s)
- Rachel Ali Rodriguez
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Christina Joya
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Rochelle M Hines
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
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10
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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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11
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Vignoli A, Oggioni G, De Maria G, Peron A, Savini MN, Zambrelli E, Chiesa V, La Briola F, Turner K, Canevini MP. Lennox-Gastaut syndrome in adulthood: Long-term clinical follow-up of 38 patients and analysis of their recorded seizures. Epilepsy Behav 2017; 77:73-78. [PMID: 29126048 DOI: 10.1016/j.yebeh.2017.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/04/2017] [Accepted: 09/10/2017] [Indexed: 11/19/2022]
Abstract
Lennox-Gastaut syndrome (LGS) is a severe epileptic encephalopathy with childhood onset that usually continues through adolescence and into adulthood. In the long term, patients with this condition still have intractable seizures, intellectual disability, behavioral problems, and physical comorbidities. The aim of this study was to describe the clinical and EEG characteristics of a group of adults with Lennox-Gastaut syndrome. We identified 38 (22 females, 16 males) patients with LGS older than age 18years at their last evaluation, with mean age of 43.3±10.6years. Median follow-up was 14.4years (range: 2-40). All of our patients had 3 or more seizure types during their clinical history. The most prevalent seizure types at follow-up were atypical absences (28/38), tonic (28/38), generalized tonic-clonic (17/38), focal (11/38), and myoclonic seizures (9/38). All patients had drug-resistant seizures. Besides epilepsy, intellectual disability and behavioral problems were prominent features. Surprisingly, paroxysmal nonepileptic seizures were reported in 3 patients. Our observations confirm the poor outcome of Lennox-Gastaut syndrome through adulthood, regardless of age at seizure onset, etiology, and history of previous West syndrome.
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Affiliation(s)
- Aglaia Vignoli
- Epilepsy Center, San Paolo Hospital, Milan, Italy; Department of Health Sciences, Università degli Studi di Milano, Italy
| | - Gaia Oggioni
- Epilepsy Center, San Paolo Hospital, Milan, Italy
| | | | - Angela Peron
- Epilepsy Center, San Paolo Hospital, Milan, Italy; Department of Health Sciences, Università degli Studi di Milano, Italy.
| | | | | | | | | | | | - Maria Paola Canevini
- Epilepsy Center, San Paolo Hospital, Milan, Italy; Department of Health Sciences, Università degli Studi di Milano, Italy
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12
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Abstract
Lennox-Gastaut syndrome (LGS) is considered an epileptic encephalopathy and is defined by a triad of multiple drug-resistant seizure types, a specific EEG pattern showing bursts of slow spike-wave complexes or generalized paroxysmal fast activity, and intellectual disability. The prevalence of LGS is estimated between 1 and 2% of all patients with epilepsy. The etiology of LGS is often divided into two groups: identifiable (genetic-structural-metabolic) in 65 to 75% of the patients and LGS of unknown cause in others. Lennox-Gastaut syndrome may be considered as secondary network epilepsy. The seizures in LGS are usually drug-resistant, and complete seizure control with resolution of intellectual and psychosocial dysfunction is often not achievable. Reduction in frequency of the most incapacitating seizures (e.g., drop attacks and tonic-clonic seizures) should be the major objective. Valproate, lamotrigine, and topiramate are considered to be the first-line drugs by many experts. Other effective antiepileptic drugs include levetiracetam, clobazam, rufinamide, and zonisamide. The ketogenic diet is an effective and well-tolerated treatment option. For patients with drug resistance, a further therapeutic option is surgical intervention. Corpus callosotomy is a palliative surgical procedure that aims at controlling the most injurious seizures. Finally, vagus nerve stimulation offers reasonable seizure improvement. The long-term outcome for patients with LGS is generally poor. This syndrome is often associated with long-term adverse effects on intellectual development, social functioning, and independent living.
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13
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Abstract
Lennox-Gastaut syndrome (LGS) is a severe pediatric epilepsy syndrome characterized by mixed seizures, cognitive decline, and generalized slow (<3 Hz) spike wave discharges on electroencephalography. Atonic seizures result in dangerous drop attacks with risks of injury and impairment of the quality of life. The seizures are frequently resistant to multiple antiepileptic (AED) drugs. Newer AEDs, such as rufinamide, are now available. When multiple AED trials fail, non-pharmacological treatments such as the ketogenic diet, vagus nerve stimulation, and epilepsy surgery, should be considered. The aim of this review is to present an updated outline of LGS and the available treatments. Although the prognosis for complete seizure control remains poor, the addition of newer therapies provides an improved hope for some of these patients and their families. Further long term randomized controlled trials are required to compare different therapeutic interventions in terms of efficacy and tolerability.
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Affiliation(s)
- Muradi H Al-Banji
- Department of Pediatrics, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia
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14
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From focal epilepsy to Dravet syndrome--Heterogeneity of the phenotype due to SCN1A mutations of the p.Arg1596 amino acid residue in the Nav1.1 subunit. Neurol Neurochir Pol 2015; 49:258-66. [PMID: 26188943 DOI: 10.1016/j.pjnns.2015.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 05/28/2015] [Accepted: 06/11/2015] [Indexed: 11/20/2022]
Abstract
OBJECTIVE The aim of this study was to analyze the intra-/interfamilial phenotypic heterogeneity due to variants at the highly evolutionary conservative p.Arg1596 residue in the Nav1.1 subunit. MATERIALS/PARTICIPANTS Among patients referred for analysis of the SCN1A gene one recurrent, heritable mutation was found in families enrolled into the study. Probands from those families even clinically diagnosed with atypical Dravet syndrome (DS), generalized epilepsy with febrile seizures plus (GEFS+), and focal epilepsy, had heterozygous p.Arg1596 His/Cys missense substitutions, c.4787G>T and c.4786C>T in the SCN1A gene. METHOD Full clinical evaluation, including cognitive development, neurological examination, EEGs, MRI was performed in probands and affected family members in developmental age. The whole SCN1A gene sequencing was performed for all probands. The exon 25, where the identified missense substitutions are localized, was directly analyzed for the other family members. RESULTS Mutation of the SCN1A p.1596Arg was identified in three families, in one case substitution p.Arg1596Cys and in two cases p.Arg1596His. Both mutations were previously described as pathogenic and causative for DS, GEFS+ and focal epilepsy. Spectrum of phenotypes among presented families with p.Arg1596 mutations shows heterogeneity ranged from asymptomatic cases, through FS and FS+ to GEFS+/Panayiotopoulos syndrome and epilepsies with and without febrile seizures, and epileptic encephalopathy such as DS. Phenotypes differ among patients displaying both focal and generalized epilepsies. Some patients demonstrated additionally Asperger syndrome and ataxia. CONCLUSION Clinical picture heterogeneity of the patients carrying mutation of the same residue indicates the involvement of the other factors influencing the SCN1A gene mutations' penetrance.
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15
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Gilchrist J, Dutton S, Diaz-Bustamante M, McPherson A, Olivares N, Kalia J, Escayg A, Bosmans F. Nav1.1 modulation by a novel triazole compound attenuates epileptic seizures in rodents. ACS Chem Biol 2014; 9:1204-12. [PMID: 24635129 PMCID: PMC4027953 DOI: 10.1021/cb500108p] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 03/17/2014] [Indexed: 12/19/2022]
Abstract
Here, we report the discovery of a novel anticonvulsant drug with a molecular organization based on the unique scaffold of rufinamide, an anti-epileptic compound used in a clinical setting to treat severe epilepsy disorders such as Lennox-Gastaut syndrome. Although accumulating evidence supports a working mechanism through voltage-gated sodium (Nav) channels, we found that a clinically relevant rufinamide concentration inhibits human (h)Nav1.1 activation, a distinct working mechanism among anticonvulsants and a feature worth exploring for treating a growing number of debilitating disorders involving hNav1.1. Subsequent structure-activity relationship experiments with related N-benzyl triazole compounds on four brain hNav channel isoforms revealed a novel drug variant that (1) shifts hNav1.1 opening to more depolarized voltages without further alterations in the gating properties of hNav1.1, hNav1.2, hNav1.3, and hNav1.6; (2) increases the threshold to action potential initiation in hippocampal neurons; and (3) greatly reduces the frequency of seizures in three animal models. Altogether, our results provide novel molecular insights into the rational development of Nav channel-targeting molecules based on the unique rufinamide scaffold, an outcome that may be exploited to design drugs for treating disorders involving particular Nav channel isoforms while limiting adverse effects.
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Affiliation(s)
- John Gilchrist
- Department
of Physiology, Johns Hopkins University,
School of Medicine, Baltimore, Maryland 21205, United States
| | - Stacey Dutton
- Department
of Human Genetics, Emory University, School
of Medicine, Atlanta, Georgia 30022, United
States
| | - Marcelo Diaz-Bustamante
- Lieber
Institute for Brain Development, Johns Hopkins
University, School of Medicine, Baltimore, Maryland 21205, United States
| | - Annie McPherson
- Department
of Human Genetics, Emory University, School
of Medicine, Atlanta, Georgia 30022, United
States
| | - Nicolas Olivares
- Lieber
Institute for Brain Development, Johns Hopkins
University, School of Medicine, Baltimore, Maryland 21205, United States
| | - Jeet Kalia
- Indian
Institute of Science Education and Research Pune, Pune, Maharashtra 411 008, India
| | - Andrew Escayg
- Department
of Human Genetics, Emory University, School
of Medicine, Atlanta, Georgia 30022, United
States
| | - Frank Bosmans
- Department
of Physiology, Johns Hopkins University,
School of Medicine, Baltimore, Maryland 21205, United States
- Solomon
H. Snyder Department of Neuroscience, Johns
Hopkins University, School of Medicine, Baltimore, Maryland 21205, United States
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16
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Lund C, Brodtkorb E, Øye AM, Røsby O, Selmer KK. CHD2 mutations in Lennox-Gastaut syndrome. Epilepsy Behav 2014; 33:18-21. [PMID: 24614520 DOI: 10.1016/j.yebeh.2014.02.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/03/2014] [Accepted: 02/03/2014] [Indexed: 12/19/2022]
Abstract
Lennox-Gastaut syndrome (LGS) is an epileptic encephalopathy with a heterogeneous etiology. In this study, we aimed to explore the role of CHD2 in LGS, as CHD2 mutations have been described recently in various epileptic encephalopathies. We have previously identified one patient with a large deletion affecting the CHD2 gene in a group of 22 patients with LGS or LGS-like epilepsy. In the remaining 17 patients without known etiology, Sanger sequencing revealed a de novo 1-bp duplication in the CHD2 gene in another patient. This mutation leads to a frameshift and, consequently, a premature stop codon 49bp downstream of the mutation. The patient had prominent myoclonic seizures and photosensitivity, thus, sharing phenotypic features with previously reported patients with CHD2-related epilepsy. In our original material of 22 patients with LGS features, we have now found two (9%) with mutations in the CHD2 gene. Our findings suggest that CHD2 mutations are important in the etiological spectrum of LGS.
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Affiliation(s)
- Caroline Lund
- National Centre for Rare Epilepsy-related Disorders, Oslo University Hospital, Oslo, Norway; National Centre for Epilepsy, SSE, Oslo University Hospital, Oslo, Norway.
| | - Eylert Brodtkorb
- Department of Neurology and Clinical Neurophysiology, St. Olav's Hospital, Trondheim, Norway; Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ane-Marte Øye
- Department of Medical Genetics, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Oddveig Røsby
- Department of Medical Genetics, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - Kaja Kristine Selmer
- National Centre for Rare Epilepsy-related Disorders, Oslo University Hospital, Oslo, Norway; Department of Medical Genetics, Oslo University Hospital, University of Oslo, Oslo, Norway
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17
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Copy number variants in adult patients with Lennox-Gastaut syndrome features. Epilepsy Res 2013; 105:110-7. [PMID: 23415449 DOI: 10.1016/j.eplepsyres.2013.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/29/2012] [Accepted: 01/18/2013] [Indexed: 12/14/2022]
Abstract
PURPOSE Lennox-Gastaut syndrome (LGS) is a severe epileptic encephalopathy with complex etiology. To explore possible genetic predispositions and causes of LGS, we have searched for copy number variants (CNVs). METHODS We studied 21 patients with LGS or LGS-like epilepsy for CNVs using whole-genome array comparative genomic hybridization (aCGH). KEY FINDINGS Eight patients (38%) carried rare CNVs that might contribute to their phenotype. The pathogenicity could be questioned in some of them, but in four patients (19%) a causative role was considered highly probable. Three had CNVs and clinical features consistent with known genetic syndromes: 22q13.3 deletion, 2q23.1 deletion, and MECP2 duplication. SIGNIFICANCE There is a high frequency of rare CNVs in adult patients with LGS-like epilepsy. The phenotypes of these background disorders may be obscured by the effects of intractable seizures and massive antiepileptic drug treatment. Previously, syndromic disorders were primarily identified by their clinical features; however, a genome wide approach with identification of the genotype might shed light on the phenotype.
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18
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Garg RK. Are SCN1A gene mutations responsible for genetic susceptibility to subacute sclerosing panencephalitis? Med Hypotheses 2011; 78:247-9. [PMID: 22098725 DOI: 10.1016/j.mehy.2011.10.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 08/17/2011] [Accepted: 10/25/2011] [Indexed: 01/06/2023]
Abstract
Dravet syndrome, characterized predominantly by myoclonus, has a striking clinical resemblance to subacute sclerosing panencephalitis (SSPE). Patients with Dravet syndrome develop significant mental decline with advancing age of affected child like in SSPE. It is well established that SCN1A gene mutations are associated with Dravet syndrome. Even periodic EEG complexes have been described in Dravet syndrome. In addition to Dravet syndrome, several other types of acute and subacute encephalopathic syndromes having clinical and electroencephalographic resemblance to SSPE are associated with SCN1A gene mutations. SSPE is a devastating progressive inflammatory disorder of the central nervous system. It is caused by persistent infection of the brain by an aberrant measles virus. Only a few of a vast number of measles infected pediatric population develop SSPE. There are several reports describing presence of SSPE is close relatives and it has been described previously in sibling and twin pairs. A genetic susceptibility for development of SSPE is likely. In fact, a variety of genetic abnormalities have already been described in patients with SSPE. It can also be argued that because of striking clinical resemblance between Dravet and various epileptic and encephalopathic syndromes associated with SCN1A gene mutations and SSPE, SCN1A gene abnormalities may also be responsible for susceptibility to SSPE in measles infected children.
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Affiliation(s)
- Ravindra Kumar Garg
- Department of Neurology, Chhatrapati Shahuji Maharaj Medical University, Uttar Pradesh, Lucknow, India.
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19
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Lund C, Brodtkorb E, Nakken K. Lennox-Gastauts syndrom - forløp og behandling. TIDSSKRIFT FOR DEN NORSKE LEGEFORENING 2011; 131:24-7. [DOI: 10.4045/tidsskr.09.1540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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20
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Yu MJ, Shi YW, Gao MM, Deng WY, Liu XR, Chen L, Long YS, Yi YH, Liao WP. Milder phenotype with SCN1A truncation mutation other than SMEI. Seizure 2010; 19:443-5. [PMID: 20630778 DOI: 10.1016/j.seizure.2010.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 06/09/2010] [Accepted: 06/17/2010] [Indexed: 10/19/2022] Open
Abstract
Till now truncation mutations of voltage-gated sodium channel alpha subunit type I (SCN1A) gene were mostly found in severe myoclonic epilepsy of infancy (SMEI) patients. In this research we first identified two novel de novo truncation mutations (S662X and M145fx148) in two patients whose phenotypes were quite milder compared with SMEI patients. One patient was diagnosed as generalized epilepsy with febrile seizures plus (GEFS+); the other had focal seizures. Both patients had good response to anti-epileptic therapy (valproate or the combination of valproate and topiramate). Our findings extended the utility of the SCN1A gene testing and further confirmed the complex relationship between genotype and phenotype of SCN1A mutations. Further work is needed to optimize the protocol for specific genetic testing in children with epilepsy.
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Affiliation(s)
- Mei-Juan Yu
- Institute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical College and Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, China
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