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Richard MA, Lupo PJ, Ehli EA, Sahin M, Krueger DA, Wu JY, Bebin EM, Au KS, Northrup H, Farach LS. Common epilepsy variants from the general population are not associated with epilepsy among individuals with tuberous sclerosis complex. Am J Med Genet A 2024; 194:e63569. [PMID: 38366765 PMCID: PMC11060940 DOI: 10.1002/ajmg.a.63569] [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: 11/27/2023] [Revised: 01/26/2024] [Accepted: 02/02/2024] [Indexed: 02/18/2024]
Abstract
Common genetic variants identified in the general population have been found to increase phenotypic risks among individuals with certain genetic conditions. Up to 90% of individuals with tuberous sclerosis complex (TSC) are affected by some type of epilepsy, yet the common variants contributing to epilepsy risk in the general population have not been evaluated in the context of TSC-associated epilepsy. Such knowledge is important to help uncover the underlying pathogenesis of epilepsy in TSC which is not fully understood, and critical as uncontrolled epilepsy is a major problem in this population. To evaluate common genetic modifiers of epilepsy, our study pooled phenotypic and genotypic data from 369 individuals with TSC to evaluate known and novel epilepsy common variants. We did not find evidence of enhanced genetic penetrance for known epilepsy variants identified across the largest genome-wide association studies of epilepsy in the general population, but identified support for novel common epilepsy variants in the context of TSC. Specifically, we have identified a novel signal in SLC7A1 that may be functionally involved in pathways relevant to TSC and epilepsy. Our study highlights the need for further evaluation of genetic modifiers in TSC to aid in further understanding of epilepsy in TSC and improve outcomes.
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Affiliation(s)
- Melissa A Richard
- Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Houston, Texas, USA
| | - Philip J Lupo
- Department of Pediatrics, Section of Hematology-Oncology, Baylor College of Medicine, Houston, Texas, USA
| | - Erik A Ehli
- Avera Institute for Human Genetics, Sioux Falls, South Dakota, USA
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Darcy A Krueger
- Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Joyce Y Wu
- Epilepsy Center, Division of Pediatric Neurology, Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
- Department of Pediatrics, Division of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Elizabeth M Bebin
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kit Sing Au
- Department of Pediatrics, Division of Medical Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Hope Northrup
- Department of Pediatrics, Division of Medical Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Laura S Farach
- Department of Pediatrics, Division of Medical Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, USA
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Lee J, Kim YO, Lim BC, Lee J. PRRT2-positive self-limited infantile epilepsy: Initial seizure characteristics and response to sodium channel blockers. Epilepsia Open 2023. [PMID: 36775847 DOI: 10.1002/epi4.12708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 02/04/2023] [Indexed: 02/14/2023] Open
Abstract
OBJECTIVE Self-limited infantile epilepsy (SeLIE) has distinctive clinical features, and the PRRT2 gene is known to be a considerable genetic cause. There have been a few studies on PRRT2-positive SeLIE only, and anti-seizure medications are often required due to frequent seizures at initial seizure onset. This study aimed to provide clinical information for the early recognition of patients with PRRT2-positive SeLIE and to propose effective anti-seizure medications for seizure control. METHODS We retrospectively reviewed 36 patients diagnosed with SeLIE with genetically confirmed pathogenic variants of PRRT2. In addition, six atypical cases with neonatal-onset seizures and unremitting after 3 years of age were included to understand the expanded clinical spectrum of PRRT2-related epilepsy. We analyzed the initial presentation, clinical course, and seizure control response to anti-seizure medications. RESULTS Patients with PRRT2-related epilepsy had characteristic seizure semiology at the initial presentation, including all afebrile, clustered (n = 23, 63.9%), short-duration (n = 33, 91.7%), and bilateral tonic-clonic seizures (n = 26, 72.2%). Genetic analysis revealed that c. 649dupC was the most common variant, and six patients had a 16p11.2 microdeletion containing the PRRT2 gene. One-third of the patients were sporadic cases without a family history of epilepsy or paroxysmal movement disorders. In the 33 patients treated with anti-seizure medications, sodium channel blockers, such as carbamazepine, were the most effective in seizure control. SIGNIFICANCE Our results delineated the clinical characteristics of PRRT2-positive SeLIE, differentiating it from other genetic infantile epilepsies and discovered the effective anti-seizure medications for initial clustered seizure control. If afebrile bilateral tonic-clonic seizures develop in a normally developed infant as a clustered pattern, PRRT2-positive SeLIE should be considered as a possible diagnosis, and sodium channel blockers should be administered as the first medication for seizure control.
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Affiliation(s)
- Jiwon Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Young Ok Kim
- Department of Pediatrics, Chonnam National University Medical School, Gwangju, South Korea
| | - Byung Chan Lim
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, South Korea
| | - Jeehun Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
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Salpietro V, Galassi Deforie V, Efthymiou S, O'Connor E, Marcé‐Grau A, Maroofian R, Striano P, Zara F, Morrow MM, Reich A, Blevins A, Sala‐Coromina J, Accogli A, Fortuna S, Alesandrini M, Au PYB, Singhal NS, Cogne B, Isidor B, Hanna MG, Macaya A, Kullmann DM, Houlden H, Männikkö R. De novo KCNA6 variants with attenuated K V 1.6 channel deactivation in patients with epilepsy. Epilepsia 2023; 64:443-455. [PMID: 36318112 PMCID: PMC10108282 DOI: 10.1111/epi.17455] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Mutations in the genes encoding neuronal ion channels are a common cause of Mendelian neurological diseases. We sought to identify novel de novo sequence variants in cases with early infantile epileptic phenotypes and neurodevelopmental anomalies. METHODS Following clinical diagnosis, we performed whole exome sequencing of the index cases and their parents. Identified channel variants were expressed in Xenopus oocytes and their functional properties assessed using two-electrode voltage clamp. RESULTS We identified novel de novo variants in KCNA6 in four unrelated individuals variably affected with neurodevelopmental disorders and seizures with onset in the first year of life. Three of the four identified mutations affect the pore-lining S6 α-helix of KV 1.6. A prominent finding of functional characterization in Xenopus oocytes was that the channel variants showed only minor effects on channel activation but slowed channel closure and shifted the voltage dependence of deactivation in a hyperpolarizing direction. Channels with a mutation affecting the S6 helix display dominant effects on channel deactivation when co-expressed with wild-type KV 1.6 or KV 1.1 subunits. SIGNIFICANCE This is the first report of de novo nonsynonymous variants in KCNA6 associated with neurological or any clinical features. Channel variants showed a consistent effect on channel deactivation, slowing the rate of channel closure following normal activation. This specific gain-of-function feature is likely to underlie the neurological phenotype in our patients. Our data highlight KCNA6 as a novel channelopathy gene associated with early infantile epileptic phenotypes and neurodevelopmental anomalies.
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Affiliation(s)
- Vincenzo Salpietro
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
- Department of Biotechnological and Applied Clinical Sciences (DISCAB)University of L'AquilaL'AquilaItaly
| | | | - Stephanie Efthymiou
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Emer O'Connor
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Anna Marcé‐Grau
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Reza Maroofian
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Unit of Pediatric NeurologyIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Medical Genetics UnitIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | | | | | | | | | - Júlia Sala‐Coromina
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Andrea Accogli
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI)University of Genoa16124 GenoaItaly
- Medical Genetics UnitIRCCS, Istituto “Giannina Gaslini”Genoa 16123Italy
| | | | - Marie Alesandrini
- Neuropediatrics UnitCentre Hospitalier Universitaire NantesNantesFrance
| | - P. Y. Billie Au
- Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of MedicineUniversity of CalgaryAlbertaCalgaryCanada
| | - Nilika Shah Singhal
- Departments of Neurology and Pediatrics, UCSF Benioff Children's HospitalUniversity of CaliforniaCaliforniaSan FranciscoUSA
| | - Benjamin Cogne
- Centre Hospitalier Universitaire NantesService de Génétique MédicaleNantesFrance
- Université de Nantes, CNRS, INSERML'Institut du ThoraxNantesFrance
| | - Bertrand Isidor
- Centre Hospitalier Universitaire NantesService de Génétique MédicaleNantesFrance
- Université de Nantes, CNRS, INSERML'Institut du ThoraxNantesFrance
| | - Michael G. Hanna
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
- Queen Square Centre for Neuromuscular DiseasesNational Hospital for Neurology and NeurosurgeryLondonUK
| | - Alfons Macaya
- Department of Paediatric Neurology, University Hospital Vall d'HebronUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - Dimitri M. Kullmann
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, University College LondonLondonUK
| | - Henry Houlden
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
| | - Roope Männikkö
- Department of Neuromuscular DiseaseUCL Institute of Neurology, University College LondonLondonUK
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Lee J, Lee C, Ki CS, Lee J. Determining the best candidates for next-generation sequencing-based gene panel for evaluation of early-onset epilepsy. Mol Genet Genomic Med 2020; 8:e1376. [PMID: 32613771 PMCID: PMC7507365 DOI: 10.1002/mgg3.1376] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/01/2020] [Accepted: 06/01/2020] [Indexed: 12/21/2022] Open
Abstract
Background Genetic testing is an emerging diagnostic approach in early‐onset epilepsy. Identification of the heterogeneous genetic causes of epilepsy may mitigate unnecessary evaluations and allow more accurate diagnosis and therapy. We aimed to uncover genetic causes of early‐onset epilepsy using next‐generation sequencing (NGS) to elucidate the diagnostic candidates and evaluate the diagnostic yield of targeted gene panel testing. Methods We evaluated 116 patients with early‐onset epilepsy developed before 2 years old and normal brain imaging using a NGS‐based targeted gene panel. Variants were classified according to their pathogenicity, and the diagnostic yield of the targeted genes and associated clinical factors were determined. Results We detected 40 disease‐causing variants with diagnostic yield of 34.5% (19 pathogenic, 21 likely pathogenic). Twelve variants were novel. The most commonly detected genes were SCN1A, associated with Dravet syndrome, and PRRT2, associated with benign familial infantile epilepsy. Other variants were identified in ARX, SCN2A, KCNQ2, PCDH19, STXBP1, DEPDC5, and SCN8A. The age of seizure onset and family history were associated with disease‐causing variants. Conclusion Next‐generation sequencing‐based targeted testing is an effective diagnostic test, with 30%–40% comparable diagnostic yield. Patients with earlier seizure onset and family history of epilepsy were the best candidates for testing. For pediatric patients with early‐onset epilepsy, genetic diagnosis is important for accurate prognosis and treatment.
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Affiliation(s)
- Jiwon Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chung Lee
- Samsung Genome Institute, Samsung Medical Center, Seoul, Korea
| | | | - Jeehun Lee
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Xiong S, Wang Y, Li H, Zhang X. Interaction among GRIK2 gene on epilepsy susceptibility in Chinese children. Acta Neurol Scand 2019; 139:540-545. [PMID: 30908586 DOI: 10.1111/ane.13089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/12/2019] [Accepted: 03/16/2019] [Indexed: 11/29/2022]
Abstract
AIMS The association of single nucleotide polymorphisms (SNPs) of glutamate receptor 2 (GRIK2) gene, as well as gene-gene interaction with the risk of early-onset epilepsy susceptibility, was studied in Chinese children. METHODS Generalized multi-factor dimension reduction (GMDR) is used to identify the optimal linkage between interaction among four SNPs and early-onset epilepsy susceptibility. Logistic regression was performed to assess association between four SNPs within GRIK2 gene and the risk of epilepsy. RESULTS The results show that the risk of epilepsy in the rs4840200-T allele carriers was significantly higher than CC (CT/TT vs CC), adjusted OR (95% CI) = 1.74 (1.31-2.20), and the carrier of rs3213607-A allele was also higher than CC (CG/GG vs CC) with adjusted OR (95% CI) = 1.61 (1.23-2.10). We did not detect significant association between rs9390754 and rs2235076 within GRIK2 gene and epilepsy risk. In the GMDR analysis for the gene/gene interaction (2-4 locus models), we found a significant two-locus model (P = 0.001) involving rs4840200 and rs9390754. The cross-validation consistency was 10/10, and the prediction error was 0.632. Participants with rs4840200-CT/TT and rs9390754-GA/AA genotype within GRIK2 gene have the highest epilepsy risk, compared to participants with rs4840200-CC and rs9390754-GG genotype within GRIK2 gene, OR (95% CI) = 2.42 (1.78-3.11), after covariates adjustment for age and gender. CONCLUSIONS Both rs4840200-T and rs3213607-A, and the interactions between rs4840200 and rs9390754 are related to the increased risk of epilepsy risk.
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Affiliation(s)
- Shunjun Xiong
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yanjun Wang
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Huijuan Li
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xiaofang Zhang
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
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Passey CC, Erramouspe J, Castellanos P, O'Donnell EC, Denton DM. Concurrent Quinidine and Phenobarbital in the Treatment of a Patient with 2 KCNT1 Mutations. Curr Ther Res Clin Exp 2019; 90:106-108. [PMID: 31388363 PMCID: PMC6677567 DOI: 10.1016/j.curtheres.2019.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/13/2019] [Indexed: 11/28/2022] Open
Abstract
Epilepsy of infancy with migrating focal seizures is a devastating pediatric neurologic disorder that often results in treatment-resistant seizure activity and developmental delay. The condition has been associated with mutations in the KCNT1 gene that cause a gain of function in neuronal sodium-activated potassium channels. Quinidine has been shown to reverse this gain of function and has recently been used to reduce seizure activity in patients with these mutations. We report the case of an infant with 2 KCNT1 mutations who experienced minor relief with quinidine and discuss the drug's important interaction with phenobarbital.
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Affiliation(s)
| | - John Erramouspe
- Idaho State University College of Pharmacy, Pocatello, Idaho
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Sandoval Karamian AG, Baumer FM. Growing identification of genetic aetiologies for neonatal-onset epilepsies: lessons from the Neonatal Seizure Registry. Acta Paediatr 2019; 108:184. [PMID: 30399203 DOI: 10.1111/apa.14608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Fiona M. Baumer
- Division of Child Neurology Department of Neurology Stanford University School of Medicine Palo Alto CA USA
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Voltage-Dependent Calcium Channels, Calcium Binding Proteins, and Their Interaction in the Pathological Process of Epilepsy. Int J Mol Sci 2018; 19:ijms19092735. [PMID: 30213136 PMCID: PMC6164075 DOI: 10.3390/ijms19092735] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 01/08/2023] Open
Abstract
As an important second messenger, the calcium ion (Ca2+) plays a vital role in normal brain function and in the pathophysiological process of different neurodegenerative diseases including Alzheimer’s disease (AD), Parkinson’s disease (PD), and epilepsy. Ca2+ takes part in the regulation of neuronal excitability, and the imbalance of intracellular Ca2+ is a trigger factor for the occurrence of epilepsy. Several anti-epileptic drugs target voltage-dependent calcium channels (VDCCs). Intracellular Ca2+ levels are mainly controlled by VDCCs located in the plasma membrane, the calcium-binding proteins (CBPs) inside the cytoplasm, calcium channels located on the intracellular calcium store (particular the endoplasmic reticulum/sarcoplasmic reticulum), and the Ca2+-pumps located in the plasma membrane and intracellular calcium store. So far, while many studies have established the relationship between calcium control factors and epilepsy, the mechanism of various Ca2+ regulatory factors in epileptogenesis is still unknown. In this paper, we reviewed the function, distribution, and alteration of VDCCs and CBPs in the central nervous system in the pathological process of epilepsy. The interaction of VDCCs with CBPs in the pathological process of epilepsy was also summarized. We hope this review can provide some clues for better understanding the mechanism of epileptogenesis, and for the development of new anti-epileptic drugs targeting on VDCCs and CBPs.
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9
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New differentially expressed genes and differential DNA methylation underlying refractory epilepsy. Oncotarget 2018; 7:87402-87416. [PMID: 27903967 PMCID: PMC5349997 DOI: 10.18632/oncotarget.13642] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/08/2016] [Indexed: 02/06/2023] Open
Abstract
Epigenetics underlying refractory epilepsy is poorly understood, especially in patients without distinctive genetic alterations. DNA methylation may affect gene expression in epilepsy without affecting DNA sequences. Herein, we analyzed genome-wide DNA methylation and gene expression in brain tissues of 10 patients with refractory epilepsy using methylated DNA immunoprecipitation linked with sequencing and mRNA Sequencing. Diverse distribution of differentially methylated genes was found in X chromosome, while differentially methylated genes appeared rarely in Y chromosome. 62 differentially expressed genes, such as MMP19, AZGP1, DES, and LGR6 were correlated with refractory epilepsy for the first time. Although general trends of differentially enriched gene ontology terms and Kyoto Encyclopedia of Genes and Genome pathways in this study are consistent with previous researches, differences also exist in many specific gene ontology terms and Kyoto Encyclopedia of Genes and Genome pathways. These findings provide a new genome-wide profiling of DNA methylation and gene expression in brain tissues of patients with refractory epilepsy, which may provide a basis for further study on the etiology and mechanisms of refractory epilepsy.
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10
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Kim Y, Bravo E, Thirnbeck CK, Smith-Mellecker LA, Kim SH, Gehlbach BK, Laux LC, Zhou X, Nordli DR, Richerson GB. Severe peri-ictal respiratory dysfunction is common in Dravet syndrome. J Clin Invest 2018; 128:1141-1153. [PMID: 29329111 DOI: 10.1172/jci94999] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 01/04/2018] [Indexed: 11/17/2022] Open
Abstract
Dravet syndrome (DS) is a severe childhood-onset epilepsy commonly due to mutations of the sodium channel gene SCN1A. Patients with DS have a high risk of sudden unexplained death in epilepsy (SUDEP), widely believed to be due to cardiac mechanisms. Here we show that patients with DS commonly have peri-ictal respiratory dysfunction. One patient had severe and prolonged postictal hypoventilation during video EEG monitoring and died later of SUDEP. Mice with an Scn1aR1407X/+ loss-of-function mutation were monitored and died after spontaneous and heat-induced seizures due to central apnea followed by progressive bradycardia. Death could be prevented with mechanical ventilation after seizures were induced by hyperthermia or maximal electroshock. Muscarinic receptor antagonists did not prevent bradycardia or death when given at doses selective for peripheral parasympathetic blockade, whereas apnea, bradycardia, and death were prevented by the same drugs given at doses high enough to cross the blood-brain barrier. When given via intracerebroventricular infusion at a very low dose, a muscarinic receptor antagonist prevented apnea, bradycardia, and death. We conclude that SUDEP in patients with DS can result from primary central apnea, which can cause bradycardia, presumably via a direct effect of hypoxemia on cardiac muscle.
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Affiliation(s)
- YuJaung Kim
- Department of Neurology and.,Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA
| | | | | | | | - Se Hee Kim
- Division of Pediatric Neurology, Northwestern University, Chicago, Illinois, USA
| | | | - Linda C Laux
- Division of Pediatric Neurology, Northwestern University, Chicago, Illinois, USA
| | | | - Douglas R Nordli
- Division of Pediatric Neurology, Northwestern University, Chicago, Illinois, USA
| | - George B Richerson
- Department of Neurology and.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, USA.,Neurology Service, Veterans Affairs Medical Center, Iowa City, Iowa, USA
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Genetic Variants Identified from Epilepsy of Unknown Etiology in Chinese Children by Targeted Exome Sequencing. Sci Rep 2017; 7:40319. [PMID: 28074849 PMCID: PMC5225856 DOI: 10.1038/srep40319] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 12/05/2016] [Indexed: 12/02/2022] Open
Abstract
Genetic factors play a major role in the etiology of epilepsy disorders. Recent genomics studies using next generation sequencing (NGS) technique have identified a large number of genetic variants including copy number (CNV) and single nucleotide variant (SNV) in a small set of genes from individuals with epilepsy. These discoveries have contributed significantly to evaluate the etiology of epilepsy in clinic and lay the foundation to develop molecular specific treatment. However, the molecular basis for a majority of epilepsy patients remains elusive, and furthermore, most of these studies have been conducted in Caucasian children. Here we conducted a targeted exome-sequencing of 63 trios of Chinese epilepsy families using a custom-designed NGS panel that covers 412 known and candidate genes for epilepsy. We identified pathogenic and likely pathogenic variants in 15 of 63 (23.8%) families in known epilepsy genes including SCN1A, CDKL5, STXBP1, CHD2, SCN3A, SCN9A, TSC2, MBD5, POLG and EFHC1. More importantly, we identified likely pathologic variants in several novel candidate genes such as GABRE, MYH1, and CLCN6. Our results provide the evidence supporting the application of custom-designed NGS panel in clinic and indicate a conserved genetic susceptibility for epilepsy between Chinese and Caucasian children.
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12
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Jiang X, Lachance M, Rossignol E. Involvement of cortical fast-spiking parvalbumin-positive basket cells in epilepsy. PROGRESS IN BRAIN RESEARCH 2016; 226:81-126. [PMID: 27323940 DOI: 10.1016/bs.pbr.2016.04.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
GABAergic interneurons of the parvalbumin-positive fast-spiking basket cells subtype (PV INs) are important regulators of cortical network excitability and of gamma oscillations, involved in signal processing and cognition. Impaired development or function of PV INs has been associated with epilepsy in various animal models of epilepsy, as well as in some genetic forms of epilepsy in humans. In this review, we provide an overview of some of the experimental data linking PV INs dysfunction with epilepsy, focusing on disorders of the specification, migration, maturation, synaptic function, or connectivity of PV INs. Furthermore, we reflect on the potential therapeutic use of cell-type specific stimulation of PV INs within active networks and on the transplantation of PV INs precursors in the treatment of epilepsy and its comorbidities.
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Affiliation(s)
- X Jiang
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - M Lachance
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - E Rossignol
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada.
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Abstract
In this article, we review the treatment options for the pediatric epileptic encephalopathies and provide an update on the new and emerging therapies targeted at the underlying pathophysiology of many of these syndromes. We illustrate how the identification of the specific genetic and autoimmune causes has made possible the evaluation and development of novel, better targeted therapies, as and at times, avoidance of potentially offending agents.
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Shbarou R, Mikati MA. The Expanding Clinical Spectrum of Genetic Pediatric Epileptic Encephalopathies. Semin Pediatr Neurol 2016; 23:134-42. [PMID: 27544470 DOI: 10.1016/j.spen.2016.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pediatric epileptic encephalopathies represent a clinically challenging and often devastating group of disorders that affect children at different stages of infancy and childhood. With the advances in genetic testing and neuroimaging, the etiologies of these epileptic syndromes are now better defined. The various encephalopathies that are reviewed in this article include the following: early infantile epileptic encephalopathy or Ohtahara syndrome, early myoclonic encephalopathy, epilepsy of infancy with migrating focal seizures, West syndrome, severe myoclonic epilepsy in infancy (Dravet syndrome), Landau-Kleffner syndrome, Lennox-Gastaut syndrome, and epileptic encephalopathy with continuous spike-and-wave during sleep. Their clinical features, prognosis as well as underlying genetic etiologies are presented and updated.
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Affiliation(s)
- Rolla Shbarou
- Department of Pediatrics and Adolescent Medicine, American University of Beirut, Lebanon
| | - Mohamad A Mikati
- Division of Pediatric Neurology, Children's Health Center, Duke University Medical Center, Durham, NC.
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15
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Do traditional anti-seizure drugs have a future? A review of potential anti-seizure drugs in clinical development. Pharmacol Res 2016; 104:38-48. [DOI: 10.1016/j.phrs.2015.12.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 12/08/2015] [Accepted: 12/08/2015] [Indexed: 12/11/2022]
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Abstract
Genetic factors contribute to the high interindividual variability in response to antiepileptic drugs. However, most genetic markers identified to date have limited sensitivity and specificity, and the value of genetic testing in guiding antiepileptic drug (AED) therapy is limited. The best defined indication for testing relates to HLA-B*15:02 genotyping to identify those individuals of South Asian ethnicity who are at high risk for developing serious adverse cutaneous reactions to carbamazepine. The indication for HLA-A*31:01 testing to identify individuals at risk for skin reactions from carbamazepine, or for CYP2C9 genotyping to identify individuals at risk for serious skin reactions from phenytoin is less compelling. The use of genetic testing to guide epilepsy treatment is likely to increase in the future, as better understanding of the function of epilepsy genes will permit the application of precision medicine targeting the biological mechanisms responsible for epilepsy in the specific individual.
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Affiliation(s)
| | - Emilio Perucca
- a 1 C. Mondino National Neurological Institute, Pavia, Italy.,b 2 Department of Internal Medicine and Therapeutics, Division of Clinical and Experimental Pharmacology, University of Pavia, Pavia, Italy
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