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Gamirova R, Shagimardanova E, Sato T, Kannon T, Gamirova R, Tajima A. Identification of potential disease-associated variants in idiopathic generalized epilepsy using targeted sequencing. J Hum Genet 2024; 69:59-67. [PMID: 37993639 DOI: 10.1038/s10038-023-01208-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/28/2023] [Accepted: 11/07/2023] [Indexed: 11/24/2023]
Abstract
Many questions remain regarding the genetics of idiopathic generalized epilepsy (IGE), a subset of genetic generalized epilepsy (GGE). We aimed to identify the candidate coding variants of epilepsy panel genes in a cohort of affected individuals, using variant frequency information from a control cohort of the same region. We performed whole-exome sequencing analysis of 121 individuals and 10 affected relatives, focusing on variants of 950 candidate genes associated with epilepsy according to the Genes4Epilepsy curated panel. We identified 168 candidate variants (CVs) in 137 of 950 candidate genes in 88 of 121 affected individuals with IGE, of which 61 were novel variants. Notably, we identified five CVs in known GGE-associated genes (CHD2, GABRA1, RORB, SCN1A, and SCN1B) in five individuals and CVs shared by affected individuals in each of four family cases for other epilepsy candidate genes. The results of this study demonstrate that IGE is a disease with high heterogeneity and provide IGE-associated CVs whose pathogenicity should be proven by future studies, including advanced functional analysis. The low detection rate of CVs in the GGE-associated genes (4.1%) in this study suggests the current incompleteness of the Genes4Epilepsy panel for the diagnosis of IGE in clinical practice.
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Affiliation(s)
- Regina Gamirova
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Japan
| | | | - Takehiro Sato
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Japan
- Department of Human Biology and Anatomy, Graduate School of Medicine, University of the Ryukyus, Nishihara, Japan
| | - Takayuki Kannon
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Japan
- Department of Biomedical Data Science, Fujita Health University School of Medicine, Toyoake, Japan
| | - Rimma Gamirova
- Department of Neurology with Courses in Psychiatry, Clinical Psychology and Medical Genetics, Kazan Federal University, Kazan, Russia.
- Laboratory of Neurocognitive Investigations, Kazan Federal University, Kazan, Russia.
| | - Atsushi Tajima
- Department of Bioinformatics and Genomics, Graduate School of Advanced Preventive Medical Sciences, Kanazawa University, Kanazawa, Japan.
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Hirsch E, French J, Scheffer IE, Bogacz A, Alsaadi T, Sperling MR, Abdulla F, Zuberi SM, Trinka E, Specchio N, Somerville E, Samia P, Riney K, Nabbout R, Jain S, Wilmshurst JM, Auvin S, Wiebe S, Perucca E, Moshé SL, Tinuper P, Wirrell EC. ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions. Epilepsia 2022; 63:1475-1499. [PMID: 35503716 DOI: 10.1111/epi.17236] [Citation(s) in RCA: 137] [Impact Index Per Article: 68.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 12/13/2022]
Abstract
In 2017, the International League Against Epilepsy (ILAE) Classification of Epilepsies described the "genetic generalized epilepsies" (GGEs), which contained the "idiopathic generalized epilepsies" (IGEs). The goal of this paper is to delineate the four syndromes comprising the IGEs, namely childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone. We provide updated diagnostic criteria for these IGE syndromes determined by the expert consensus opinion of the ILAE's Task Force on Nosology and Definitions (2017-2021) and international external experts outside our Task Force. We incorporate current knowledge from recent advances in genetic, imaging, and electroencephalographic studies, together with current terminology and classification of seizures and epilepsies. Patients that do not fulfill criteria for one of these syndromes, but that have one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic-clonic and myoclonic-tonic-clonic seizures, with 2.5-5.5 Hz generalized spike-wave should be classified as having GGE. Recognizing these four IGE syndromes as a special grouping among the GGEs is helpful, as they carry prognostic and therapeutic implications.
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Affiliation(s)
- Edouard Hirsch
- Francis Rohmer Neurology Epilepsy Units, National Institute of Health and Medical Research 1258, Federation of Translational Medicine of Strasbourg, Strasbourg University, Strasbourg, France
| | - Jacqueline French
- New York University Grossman School of Medicine and NYU Langone Health, New York, New York, USA
| | - Ingrid E Scheffer
- Austin Health and Royal Children's Hospital, Florey Institute, Murdoch Children's Research Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Alicia Bogacz
- Institute of Neurology, Clinical Hospital, Faculty of Medicine, University of the Republic, Montevideo, Uruguay
| | - Taoufik Alsaadi
- Department of Neurology, American Center for Psychiatry and Neurology, Abu Dhabi, United Arab Emirates
| | - Michael R Sperling
- Department of Neurology, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Fatema Abdulla
- Salmaniya Medical Complex-Government Hospital, Manama, Bahrain
| | - Sameer M Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children and Institute of Health & Wellbeing, University of Glasgow, member of EpiCARE, Glasgow, UK
| | - Eugen Trinka
- Department of Neurology and Neuroscience Institute, Christian Doppler University Hospital, Paracelsus Medical University, Center for Cognitive Neuroscience, member of EpiCARE, Salzburg, Austria.,Department of Public Health, Health Services Research, and Health Technology Assessment, University for Health Sciences, Medical Informatics, and Technology, Hall in Tirol, Austria
| | - Nicola Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, Scientific Institute for Research and Health Care, member of EpiCARE, Rome, Italy
| | - Ernest Somerville
- Prince of Wales Hospital, University of New South Wales, Sydney, New South Wales, Australia
| | - Pauline Samia
- Department of Pediatrics and Child Health, Aga Khan University, East Africa, Nairobi, Kenya
| | - Kate Riney
- Neurosciences Unit, Queensland Children's Hospital, South Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Rima Nabbout
- Reference Center for Rare Epilepsies, Department of Pediatric Neurology, Necker-Enfants Malades Hospital, Public Hospital Network of Paris, member of EpiCARE, Imagine Institute, National Institute of Health and Medical Research, Mixed Unit of Research 1163, University of Paris, Paris, France
| | | | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Stephane Auvin
- Pediatric Neurology, Public Hospital Network of Paris, Robert Debré Hospital, NeuroDiderot, National Institute of Health and Medical Research, Department Medico-Universitaire, Innovation Robert-Debré, University of Paris, Paris, France.,University Institute of France, Paris, France
| | - Samuel Wiebe
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Emilio Perucca
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Solomon L Moshé
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, and Departments of Neuroscience and Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, USA
| | - Paolo Tinuper
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,Institute of Neurological Sciences, Scientific Institute for Research and Health Care, member of EpiCARE, Bologna, Italy
| | - Elaine C Wirrell
- Divisions of Child and Adolescent Neurology and Epilepsy, Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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Long Non-Coding RNAs and Related Molecular Pathways in the Pathogenesis of Epilepsy. Int J Mol Sci 2019; 20:ijms20194898. [PMID: 31581735 PMCID: PMC6801574 DOI: 10.3390/ijms20194898] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 09/27/2019] [Accepted: 10/02/2019] [Indexed: 02/07/2023] Open
Abstract
Epilepsy represents one of the most common neurological disorders characterized by abnormal electrical activity in the central nervous system (CNS). Recurrent seizures are the cardinal clinical manifestation. Although it has been reported that the underlying pathological processes include inflammation, changes in synaptic strength, apoptosis, and ion channels dysfunction, currently the pathogenesis of epilepsy is not yet completely understood. Long non-coding RNAs (lncRNAs), a class of long transcripts without protein-coding capacity, have emerged as regulatory molecules that are involved in a wide variety of biological processes. A growing number of studies reported that lncRNAs participate in the regulation of pathological processes of epilepsy and they are dysregulated during epileptogenesis. Moreover, an aberrant expression of lncRNAs linked to epilepsy has been observed both in patients and in animal models. In this review, we summarize latest advances concerning the mechanisms of action and the involvement of the most dysregulated lncRNAs in epilepsy. However, the functional roles of lncRNAs in the disease pathogenesis are still to be explored and we are only at the beginning. Additional studies are needed for the complete understanding of the underlying mechanisms and they would result in the use of lncRNAs as diagnostic biomarkers and novel therapeutic targets.
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Wang M, Greenberg DA, Stewart WCL. Replication, reanalysis, and gene expression: ME2 and genetic generalized epilepsy. Epilepsia 2019; 60:539-546. [PMID: 30719716 DOI: 10.1111/epi.14654] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 12/28/2018] [Accepted: 01/04/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Genetic generalized epilepsy (GGE) consists of epileptic syndromes with overlapping symptoms and is considered to be largely genetic. Previous cosegregation and association studies have pointed to malic enzyme 2 (ME2) as a candidate susceptibility gene for adolescent-onset GGE. In this article, we present new evidence supporting ME2's involvement in GGE. METHODS To definitively test ME2's influence on GGE, we used 3 different approaches. First, we compared a newly recruited GGE cohort with an ethnically matched reference sample from 1000 Genomes Project, using an efficient test of association (POPFAM+). Second, we used POPFAM+ to reanalyze a previously collected data set, wherein the original controls were replaced with ethnically matched reference samples to minimize the confounding effect of population stratification. Third, in a post hoc analysis of expression data from healthy human prefrontal cortex, we identified single nucleotide polymorphisms (SNPs) influencing ME2 messenger RNA (mRNA) expression; and then we tested those same SNPs for association with GGE in a large case-control cohort. RESULTS First, in the analysis of our newly recruited GGE Cohort, we found a strong association between an ME2 SNP and GGE (P = 0.0006 at rs608781). Second, in the reanalysis of previously collected data, we confirmed the Greenberg et al (2005) finding of a GGE-associated ME2 risk haplotype. Third, in the post hoc ME2 expression analysis, we found evidence for a possible link between GGE and ME2 gene expression in human brain. SIGNIFICANCE Overall, our research, and the research of others, provides compelling evidence that ME2 influences susceptibility to adolescent-onset GGE.
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Affiliation(s)
- Meng Wang
- The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio
| | | | - William C L Stewart
- The Research Institute at Nationwide Children's Hospital, Nationwide Children's Hospital, Columbus, Ohio.,Department of Statistics, The Ohio State University, Columbus, Ohio.,Department of Pediatrics, The Ohio State University, Columbus, Ohio
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Abstract
Idiopathic generalized epilepsies (IGE) are characterized by normal background EEG activity and generalized interictal spike-and-wave discharges in the absence of any evidence of brain lesion. Absence epilepsies are the prototypes of IGEs. In childhood and juvenile absence epilepsies, by definition, all patients manifest absence seizures associated with an EEG pattern of generalized spike-wave (GSW) discharges. In juvenile myoclonic epilepsy, myoclonic jerks, usually affecting shoulders and arms bilaterally and appearing upon awakening, are the most characteristic clinical feature. Myoclonic jerks are accompanied on the EEG by generalized spike/polyspike-and-wave (GSW, GPWS) complexes at 3.5-6Hz. Idiopathic generalized epilepsy with generalized tonic-clonic seizures only is a broad and nonspecific category including all patients with generalized tonic-clonic seizures and an interictal EEG pattern of GSW discharges. Despite the strong heritability and the recent advances in genetic technology, the genetic basis of IGEs remains largely elusive and only in a small minority of patients with classic IGE phenotypes is a monogenic cause identified. Early myoclonic encephalopathy (EME), early infantile encephalopathy with suppression bursts, West syndrome, and Lennox-Gastaut syndrome, once classified among the generalized epilepsies, are now considered to be epileptic encephalopathies. Among them, only Lennox-Gastaut syndrome is characterized by prominent generalized clinical and EEG features.
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Affiliation(s)
- Renzo Guerrini
- Neuroscience Department, Children's Hospital A. Meyer-University of Florence, Florence, Italy.
| | - Carla Marini
- Neuroscience Department, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Carmen Barba
- Neuroscience Department, Children's Hospital A. Meyer-University of Florence, Florence, Italy
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An H, Williams NG, Shelkovnikova TA. NEAT1 and paraspeckles in neurodegenerative diseases: A missing lnc found? Noncoding RNA Res 2018; 3:243-252. [PMID: 30533572 PMCID: PMC6257911 DOI: 10.1016/j.ncrna.2018.11.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/13/2018] [Accepted: 11/14/2018] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases are among the most common causes of disability worldwide. Although neurodegenerative diseases are heterogeneous in both their clinical features and the underlying physiology, they are all characterised by progressive loss of specific neuronal populations. Recent experimental evidence suggests that long non-coding RNAs (lncRNAs) play important roles in the CNS in health and disease. Nuclear Paraspeckle Assembly Transcript 1 (NEAT1) is an abundant, ubiquitously expressed lncRNA, which forms a scaffold for a specific RNA granule in the nucleus, or nuclear body, the paraspeckle. Paraspeckles act as molecular hubs for cellular processes commonly affected by neurodegeneration. Transcriptomic analyses of the diseased human tissue have revealed altered NEAT1 levels in the CNS in major neurodegenerative disorders as well as in some disease models. Although it is clear that changes in NEAT1 expression (and in some cases, paraspeckle assembly) accompany neuronal damage, our understanding of NEAT1 contribution to the disease pathogenesis is still rudimentary. In this review, we have summarised the available knowledge on NEAT1 involvement in the molecular processes linked to neurodegeneration and on NEAT1 dysregulation in this type of disease, with a special focus on amyotrophic lateral sclerosis. The goal of this review is to attract the attention of researchers in the field of neurodegeneration to NEAT1 and paraspeckles.
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Affiliation(s)
- Haiyan An
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Park Place, Cardiff, CF10 3AT, United Kingdom
| | - Non G Williams
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Park Place, Cardiff, CF10 3AT, United Kingdom
| | - Tatyana A Shelkovnikova
- Medicines Discovery Institute, School of Biosciences, Cardiff University, Park Place, Cardiff, CF10 3AT, United Kingdom
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Sun Y, Seneviratne U, Perucca P, Chen Z, Kee MT, O'Brien TJ, D'Souza W, Kwan P. Generalized polyspike train: An EEG biomarker of drug-resistant idiopathic generalized epilepsy. Neurology 2018; 91:e1822-e1830. [PMID: 30315071 DOI: 10.1212/wnl.0000000000006472] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 08/01/2018] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify clinical and EEG biomarkers of drug resistance in adults with idiopathic generalized epilepsy. METHODS We conducted a case-control study consisting of a discovery cohort and a replication cohort independently assessed at 2 different centers. In each center, patients with the idiopathic generalized epilepsy phenotype and generalized spike-wave discharges on EEG were classified as drug-resistant or drug-responsive. EEG changes were classified into predefined patterns and compared between the 2 groups in the discovery cohort. Factors associated with drug resistance in multivariable analysis were tested in the replication cohort. RESULTS The discovery cohort included 85 patients (29% drug-resistant and 71% drug-responsive). Their median age at assessment was 32 years and 50.6% were female. Multivariable analysis showed that higher number of seizure types ever experienced (3 vs 1: odds ratio [OR] = 31.1, 95% confidence interval [CI]: 4.5-214, p < 0.001; 3 vs 2: OR = 14.6, 95% CI: 2.3-93.1, p = 0.004) and generalized polyspike train (burst of generalized rhythmic spikes lasting less than 1 second) during sleep were associated with drug resistance (OR = 10.8, 95% CI: 2.4-49.4, p = 0.002). When these factors were tested in the replication cohort of 80 patients (27.5% drug-resistant and 72.5% drug-responsive; 71.3% female; median age 27.5 years), the proportion of patients with generalized polyspike train during sleep was also higher in the drug-resistant group (OR = 4.0, 95% CI: 1.35-11.8, p = 0.012). CONCLUSION Generalized polyspike train during sleep may be an EEG biomarker for drug resistance in adults with idiopathic generalized epilepsy.
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Affiliation(s)
- Yanping Sun
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia
| | - Udaya Seneviratne
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia
| | - Piero Perucca
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia
| | - Zhibin Chen
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia
| | - Meng Tan Kee
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia
| | - Terence J O'Brien
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia.
| | - Wendyl D'Souza
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia
| | - Patrick Kwan
- From the Department of Neurology (Y.S.), The Affiliated Hospital of Qingdao University, Qingdao, China; Department of Neurology (Y.S.), Xuanwu Hospital, Capital Medical University, Beijing, China; Departments of Neurology (Y.S., P.P., M.K.T., T.J.O., P.K.) and Medicine (P.P., Z.C., T.J.O., P.K.), The Royal Melbourne Hospital, The University of Melbourne, Victoria; Department of Medicine (U.S., W.D.), St. Vincent's Hospital Melbourne, The University of Melbourne, Victoria; Department of Medicine, The School of Clinical Sciences at Monash Health (U.S.), and Departments of Neuroscience, The Central Clinical School (P.P., T.J.O., P.K.), Monash University, Victoria; and Department of Neurology (P.P., T.J.O., P.K.), The Alfred Hospital, Victoria, Australia.
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Gao K, Zhang Y, Zhang L, Kong W, Xie H, Wang J, Wu Y, Wu X, Liu X, Zhang Y, Zhang F, Yu ACH, Jiang Y. Large De Novo Microdeletion in Epilepsy with Intellectual and Developmental Disabilities, with a Systems Biology Analysis. ADVANCES IN NEUROBIOLOGY 2018; 21:247-266. [DOI: 10.1007/978-3-319-94593-4_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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9
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The long non-coding RNA NEAT1 is responsive to neuronal activity and is associated with hyperexcitability states. Sci Rep 2017; 7:40127. [PMID: 28054653 PMCID: PMC5214838 DOI: 10.1038/srep40127] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 12/02/2016] [Indexed: 11/09/2022] Open
Abstract
Despite their abundance, the molecular functions of long non-coding RNAs in mammalian nervous systems remain poorly understood. Here we show that the long non-coding RNA, NEAT1, directly modulates neuronal excitability and is associated with pathological seizure states. Specifically, NEAT1 is dynamically regulated by neuronal activity in vitro and in vivo, binds epilepsy-associated potassium channel-interacting proteins including KCNAB2 and KCNIP1, and induces a neuronal hyper-potentiation phenotype in iPSC-derived human cortical neurons following antisense oligonucleotide knockdown. Next generation sequencing reveals a strong association of NEAT1 with increased ion channel gene expression upon activation of iPSC-derived neurons following NEAT1 knockdown. Furthermore, we show that while NEAT1 is acutely down-regulated in response to neuronal activity, repeated stimulation results in NEAT1 becoming chronically unresponsive in independent in vivo rat model systems relevant to temporal lobe epilepsy. We extended previous studies showing increased NEAT1 expression in resected cortical tissue from high spiking regions of patients suffering from intractable seizures. Our results indicate a role for NEAT1 in modulating human neuronal activity and suggest a novel mechanistic link between an activity-dependent long non-coding RNA and epilepsy.
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10
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Wight JE, Nguyen V, Medina MT, Patterson C, Durón RM, Molina Y, Lin Y, Martínez‐Juárez IE, Ochoa A, Jara‐Prado A, Tanaka M, Bai D, Aftab S, Bailey JN, Delgado‐Escueta AV. Chromosome loci vary by juvenile myoclonic epilepsy subsyndromes: linkage and haplotype analysis applied to epilepsy and EEG 3.5-6.0 Hz polyspike waves. Mol Genet Genomic Med 2016; 4:197-210. [PMID: 27066514 PMCID: PMC4799870 DOI: 10.1002/mgg3.195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 11/09/2015] [Accepted: 11/12/2015] [Indexed: 12/15/2022] Open
Abstract
Juvenile myoclonic epilepsy (JME), the most common genetic epilepsy, remains enigmatic because it is considered one disease instead of several diseases. We ascertained three large multigenerational/multiplex JME pedigrees from Honduras with differing JME subsyndromes, including Childhood Absence Epilepsy evolving to JME (CAE/JME; pedigree 1), JME with adolescent onset pyknoleptic absence (JME/pA; pedigree 2), and classic JME (cJME; pedigree 3). All phenotypes were validated, including symptomatic persons with various epilepsies, asymptomatic persons with EEG 3.5-6.0 Hz polyspike waves, and asymptomatic persons with normal EEGs. Two-point parametric linkage analyses were performed with 5185 single-nucleotide polymorphisms on individual pedigrees and pooled pedigrees using four diagnostic models based on epilepsy/EEG diagnoses. Haplotype analyses of the entire genome were also performed for each individual. In pedigree 1, haplotyping identified a 34 cM region in 2q21.2-q31.1 cosegregating with all affected members, an area close to 2q14.3 identified by linkage (Z max = 1.77; pedigree 1). In pedigree 2, linkage and haplotyping identified a 44 cM cosegregating region in 13q13.3-q31.2 (Z max = 3.50 at 13q31.1; pooled pedigrees). In pedigree 3, haplotyping identified a 6 cM cosegregating region in 17q12. Possible cosegregation was also identified in 13q14.2 and 1q32 in pedigree 3, although this could not be definitively confirmed due to the presence of uninformative markers in key individuals. Differing chromosome regions identified in specific JME subsyndromes may contain separate JME disease-causing genes, favoring the concept of JME as several distinct diseases. Whole-exome sequencing will likely identify a CAE/JME gene in 2q21.2-2q31.1, a JME/pA gene in 13q13.3-q31.2, and a cJME gene in 17q12.
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Affiliation(s)
- Jenny E. Wight
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Viet‐Huong Nguyen
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Marco T. Medina
- GENESS International ConsortiumLos AngelesCalifornia
- National Autonomous University of HondurasTegucigalpaHonduras
| | - Christopher Patterson
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Reyna M. Durón
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- National Autonomous University of HondurasTegucigalpaHonduras
- Universidad Tecnológica Centroamericana (UNITEC)TegucigalpaHonduras
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Yolly Molina
- GENESS International ConsortiumLos AngelesCalifornia
- National Autonomous University of HondurasTegucigalpaHonduras
| | - Yu‐Chen Lin
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
| | - Iris E. Martínez‐Juárez
- GENESS International ConsortiumLos AngelesCalifornia
- National Institute of Neurology and NeurosurgeryMexico CityMexico
| | - Adriana Ochoa
- GENESS International ConsortiumLos AngelesCalifornia
- National Institute of Neurology and NeurosurgeryMexico CityMexico
| | - Aurelio Jara‐Prado
- GENESS International ConsortiumLos AngelesCalifornia
- National Institute of Neurology and NeurosurgeryMexico CityMexico
| | - Miyabi Tanaka
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Dongsheng Bai
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Sumaya Aftab
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
| | - Julia N. Bailey
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of EpidemiologyFielding School of Public Health at UCLALos AngelesCalifornia
| | - Antonio V. Delgado‐Escueta
- Epilepsy Genetics/Genomics LaboratoriesVA GLAHS – West Los AngelesLos AngelesCalifornia
- GENESS International ConsortiumLos AngelesCalifornia
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCalifornia
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11
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Abstract
Epilepsy is a group of disorders characterized by recurrent seizures, and is one of the most common neurological conditions. The genetic basis of epilepsy is clear from epidemiological studies and from rare gene discoveries in large families. The three major classes of epilepsy disorders are genetic generalized, focal and encephalopathic epilepsies, with several specific disorders within each class. Advances in genomic technologies that facilitate genome-wide discovery of both common and rare variants have led to a rapid increase in our understanding of epilepsy genetics. Copy number variant and genome-wide association studies have contributed to our understanding of the complex genetic architecture of generalized epilepsy, while genetic insights into the focal epilepsies and epileptic encephalopathies have come primarily from exome sequencing. It is increasingly clear that epilepsy is genetically heterogeneous, and novel gene discoveries have moved the field beyond the known contribution of ion channels to implicate chromatin remodeling, transcriptional regulation and regulation of the mammalian target of rapamycin (mTOR) protein in the etiology of epilepsy. Such discoveries pave the way for new therapeutics, some of which are already being studied. In this review, we discuss the rapid pace of gene discovery in epilepsy, as facilitated by genomic technologies, and highlight several novel genes and potential therapies.
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Affiliation(s)
- Candace T Myers
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Heather C Mefford
- Department of Pediatrics, Division of Genetic Medicine, University of Washington, Seattle, WA, 98195, USA.
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12
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Epileptic spasms and early-onset photosensitive epilepsy in Patau syndrome: An EEG study. Brain Dev 2015; 37:704-13. [PMID: 25459971 DOI: 10.1016/j.braindev.2014.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 10/06/2014] [Accepted: 10/09/2014] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Patau syndrome, trisomy 13, is the third commonest autosomal trisomy. It is associated with a 25-50% prevalence of epilepsy, but detailed electroclinical descriptions are rare. The occurrence of early-onset photosensitivity has recently been reported in single patients. MATERIALS/PATIENTS We collected electroclinical data on 8 infants (age range from 2 months to 3 years and 9 months, median: 17 months) with Patau syndrome referred for an EEG in our Clinical Neurophysiology Department between 1991 and 2011. METHODS All EEGs, case-notes, cytogenetic diagnosis and neuroimaging when available were reviewed; data on the occurrence of seizures, epileptiform discharges, photoparoxysmal response and their characteristics in terms of positive frequencies, latencies, grade and duration were noted and analysed. RESULTS Two patients had been previously diagnosed with epilepsy (one with tonic spasms and one with multiple seizure types). We found 3 patients with photosensitive myoclonic epilepsy (37.5%), and one with non-photosensitive myoclonic epilepsy. We also recorded non-epileptic myoclonic jerks in one patient known to suffer from epileptic spasms. Among photosensitive patients we found self-limited, Waltz's grade 2-4, spike-wave/polyspike-wave discharges in low, medium and high frequency ranges in two patients and in the high frequency range in the third patient, with latencies and duration from less than 1s to a maximum of 9s. CONCLUSIONS In our cohort of Patau syndrome patients, we found a high prevalence of spasms and photic-induced myoclonic jerks. Photosensitivity shows an unusual early age of onset.
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13
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Lesca G, Depienne C. Epilepsy genetics: the ongoing revolution. Rev Neurol (Paris) 2015; 171:539-57. [PMID: 26003806 DOI: 10.1016/j.neurol.2015.01.569] [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: 10/01/2014] [Revised: 12/24/2014] [Accepted: 01/20/2015] [Indexed: 01/04/2023]
Abstract
Epilepsies have long remained refractory to gene identification due to several obstacles, including a highly variable inter- and intrafamilial expressivity of the phenotypes, a high frequency of phenocopies, and a huge genetic heterogeneity. Recent technological breakthroughs, such as array comparative genomic hybridization and next generation sequencing, have been leading, in the past few years, to the identification of an increasing number of genomic regions and genes in which mutations or copy-number variations cause various epileptic disorders, revealing an enormous diversity of pathophysiological mechanisms. The field that has undergone the most striking revolution is that of epileptic encephalopathies, for which most of causing genes have been discovered since the year 2012. Some examples are the continuous spike-and-waves during slow-wave sleep and Landau-Kleffner syndromes for which the recent discovery of the role of GRIN2A mutations has finally confirmed the genetic bases. These new technologies begin to be used for diagnostic applications, and the main challenge now resides in the interpretation of the huge mass of variants detected by these methods. The identification of causative mutations in epilepsies provides definitive confirmation of the clinical diagnosis, allows accurate genetic counselling, and sometimes permits the development of new appropriate and specific antiepileptic therapies. Future challenges include the identification of the genetic or environmental factors that modify the epileptic phenotypes caused by mutations in a given gene and the understanding of the role of somatic mutations in sporadic epilepsies.
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Affiliation(s)
- G Lesca
- Service de génétique, groupement hospitalier Est, hospices civils de Lyon, 59, boulevard Pinel, 69677 Bron, France; Université Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69100 Villeurbanne, France; CRNL, CNRS UMR 5292, Inserm U1028, bâtiment IMBL, 11, avenue Jean-Capelle, 69621 Villeurbanne cedex, France.
| | - C Depienne
- Département de génétique et cytogénétique, hôpital Pitié-Salpêtrière, AP-HP, 47-83, boulevard de l'Hôpital, 75651 Paris cedex 13, France; Sorbonne universités, UPMC université Paris 06, 4, place Jussieu, 75005 Paris, France; ICM, CNRS UMR 7225, Inserm U1127, 47, boulevard de l'Hôpital, 75651 Paris cedex 13, France
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14
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Tyler AL, McGarr TC, Beyer BJ, Frankel WN, Carter GW. A genetic interaction network model of a complex neurological disease. GENES BRAIN AND BEHAVIOR 2014; 13:831-40. [PMID: 25251056 PMCID: PMC4241132 DOI: 10.1111/gbb.12178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 08/26/2014] [Accepted: 09/18/2014] [Indexed: 12/05/2022]
Abstract
Absence epilepsy (AE) is a complex, heritable disease characterized by a brief disruption of normal behavior and accompanying spike wave discharges (SWD) on the electroencephalogram. Only a handful of genes has been definitively associated with AE in humans and rodent models. Most studies suggest that genetic interactions play a large role in the etiology and severity of AE, but mapping and understanding their architecture remains a challenge, requiring new computational approaches. Here we use Combined Analysis of Pleiotropy and Epistasis (CAPE) to detect and interpret genetic interactions in a meta-population derived from three C3H x B6 strain crosses, each of which is fixed for a different SWD-causing mutation. Although each mutation causes SWD through a different molecular mechanism, the phenotypes caused by each mutation are exacerbated on the C3H genetic background compared with B6, suggesting common modifiers. By combining information across two phenotypic measures – SWD duration and frequency – CAPE revealed a large, directed genetic network consisting of suppressive and enhancing interactions between loci on 10 chromosomes. These results illustrate the power of CAPE in identifying novel modifier loci and interactions in a complex neurological disease, towards a more comprehensive view of its underlying genetic architecture.
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Affiliation(s)
- A L Tyler
- The Jackson Laboratory, Bar Harbor, ME, USA
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15
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Qu J, Zhang Y, Yang ZQ, Mao XY, Zhou BT, Yin JY, He H, Li XP, Long HY, Lv N, Xu XJ, Xiao B, Zhang Y, Tang Q, Hu DL, Zhou HH, Liu ZQ. Gene-wide tagging study of the association between KCNT1 polymorphisms and the susceptibility and efficacy of genetic generalized epilepsy in Chinese population. CNS Neurosci Ther 2013; 20:140-6. [PMID: 24279416 DOI: 10.1111/cns.12169] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 08/06/2013] [Accepted: 08/07/2013] [Indexed: 11/29/2022] Open
Abstract
AIMS The causes of genetic generalized epilepsies (GGEs) are still uncertain now. Some studies found that the human potassium channel, subfamily T, member 1 (KCNT1) is the candidate gene causing malignant migrating partial seizures of infancy and autosomal dominant nocturnal frontal lobe epilepsy which are all rare genetic generalized epilepsies. The aims of this study were going to evaluate the association between KCNT1 common variations and the susceptibility and drug resistance of genetic generalized epilepsies in Chinese population. METHODS The allele-specific MALDI-TOF mass spectrometry method was used to assess 17 tagSNPs (tagged single-nucleotide polymorphisms) of KCNT1 in 284 healthy Chinese controls and 483 Chinese GGEs patients including 279 anti-epileptic drug-responsive patients and 204 drug-resistant patients. RESULTS Genotype distributions of all the selected tagSNPs were consistent with Hardy-Weinberg equilibrium in GGEs and healthy controls. None of the all 17 tagSNPs alleles were found to be related with the susceptibility and drug resistance of genetic generalized epilepsies. The frequencies of haplotype 5 and haplotype 1 were significantly lower in GGEs than that in healthy controls (2% vs. 4%, OR = 0.47 [0.27-0.94], P = 0.03) and obviously higher in drug-resistant patients than that in drug-response patients (6% vs. 3%, OR = 2.56 [1.23-5.35], P = 0.01). However, after the correction of multiple comparisons with Bonferroni's method, we found that the above two haplotypes were not associated with the susceptibility and drug resistance in GGEs and healthy controls. CONCLUSION This gene-wide tagging study revealed no association between KCNT1 17 common variations and susceptibility of GGEs or AEDs (anti-epileptic drugs) efficacy of genetic generalized epilepsies in Chinese population.
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Affiliation(s)
- Jian Qu
- Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University Xiangya School of Medicine, Changsha, China
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16
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Parker MD, Boron WF. The divergence, actions, roles, and relatives of sodium-coupled bicarbonate transporters. Physiol Rev 2013; 93:803-959. [PMID: 23589833 PMCID: PMC3768104 DOI: 10.1152/physrev.00023.2012] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mammalian Slc4 (Solute carrier 4) family of transporters is a functionally diverse group of 10 multi-spanning membrane proteins that includes three Cl-HCO3 exchangers (AE1-3), five Na(+)-coupled HCO3(-) transporters (NCBTs), and two other unusual members (AE4, BTR1). In this review, we mainly focus on the five mammalian NCBTs-NBCe1, NBCe2, NBCn1, NDCBE, and NBCn2. Each plays a specialized role in maintaining intracellular pH and, by contributing to the movement of HCO3(-) across epithelia, in maintaining whole-body pH and otherwise contributing to epithelial transport. Disruptions involving NCBT genes are linked to blindness, deafness, proximal renal tubular acidosis, mental retardation, and epilepsy. We also review AE1-3, AE4, and BTR1, addressing their relevance to the study of NCBTs. This review draws together recent advances in our understanding of the phylogenetic origins and physiological relevance of NCBTs and their progenitors. Underlying these advances is progress in such diverse disciplines as physiology, molecular biology, genetics, immunocytochemistry, proteomics, and structural biology. This review highlights the key similarities and differences between individual NCBTs and the genes that encode them and also clarifies the sometimes confusing NCBT nomenclature.
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Affiliation(s)
- Mark D Parker
- Dept. of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106-4970, USA.
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17
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Michelucci R, Pasini E, Riguzzi P, Volpi L, Dazzo E, Nobile C. Genetics of epilepsy and relevance to current practice. Curr Neurol Neurosci Rep 2012; 12:445-55. [PMID: 22618127 DOI: 10.1007/s11910-012-0281-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Genetic factors are likely to play a major role in many epileptic conditions, spanning from classical idiopathic (genetic) generalized epilepsies to epileptic encephalopathies and focal epilepsies. In this review we describe the genetic advances in progressive myoclonus epilepsies, which are strictly monogenic disorders, genetic generalized epilepsies, mostly exhibiting complex genetic inheritance, and SCN1A-related phenotypes, namely genetic generalized epilepsy with febrile seizure plus and Dravet syndrome. Particular attention is devoted to a form of familial focal epilepsies, autosomal-dominant lateral temporal epilepsy, which is a model of non-ion genetic epilepsies. This condition is associated with mutations of the LGI1 gene, whose protein is secreted from the neurons and exerts its action on a number of targets, influencing cortical development and neuronal maturation.
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Affiliation(s)
- Roberto Michelucci
- Unit of Neurology, IRCCS Institute of Neurological Sciences, Bellaria Hospital, Via Altura 3, 40139, Bologna, Italy.
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18
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Steffens M, Leu C, Ruppert AK, Zara F, Striano P, Robbiano A, Capovilla G, Tinuper P, Gambardella A, Bianchi A, La Neve A, Crichiutti G, de Kovel CGF, Kasteleijn-Nolst Trenité D, de Haan GJ, Lindhout D, Gaus V, Schmitz B, Janz D, Weber YG, Becker F, Lerche H, Steinhoff BJ, Kleefuß-Lie AA, Kunz WS, Surges R, Elger CE, Muhle H, von Spiczak S, Ostertag P, Helbig I, Stephani U, Møller RS, Hjalgrim H, Dibbens LM, Bellows S, Oliver K, Mullen S, Scheffer IE, Berkovic SF, Everett KV, Gardiner MR, Marini C, Guerrini R, Lehesjoki AE, Siren A, Guipponi M, Malafosse A, Thomas P, Nabbout R, Baulac S, Leguern E, Guerrero R, Serratosa JM, Reif PS, Rosenow F, Mörzinger M, Feucht M, Zimprich F, Kapser C, Schankin CJ, Suls A, Smets K, De Jonghe P, Jordanova A, Caglayan H, Yapici Z, Yalcin DA, Baykan B, Bebek N, Ozbek U, Gieger C, Wichmann HE, Balschun T, Ellinghaus D, Franke A, Meesters C, Becker T, Wienker TF, Hempelmann A, Schulz H, Rüschendorf F, Leber M, Pauck SM, Trucks H, Toliat MR, Nürnberg P, Avanzini G, Koeleman BPC, Sander T. Genome-wide association analysis of genetic generalized epilepsies implicates susceptibility loci at 1q43, 2p16.1, 2q22.3 and 17q21.32. Hum Mol Genet 2012; 21:5359-72. [PMID: 22949513 DOI: 10.1093/hmg/dds373] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Genetic generalized epilepsies (GGEs) have a lifetime prevalence of 0.3% and account for 20-30% of all epilepsies. Despite their high heritability of 80%, the genetic factors predisposing to GGEs remain elusive. To identify susceptibility variants shared across common GGE syndromes, we carried out a two-stage genome-wide association study (GWAS) including 3020 patients with GGEs and 3954 controls of European ancestry. To dissect out syndrome-related variants, we also explored two distinct GGE subgroups comprising 1434 patients with genetic absence epilepsies (GAEs) and 1134 patients with juvenile myoclonic epilepsy (JME). Joint Stage-1 and 2 analyses revealed genome-wide significant associations for GGEs at 2p16.1 (rs13026414, P(meta) = 2.5 × 10(-9), OR[T] = 0.81) and 17q21.32 (rs72823592, P(meta) = 9.3 × 10(-9), OR[A] = 0.77). The search for syndrome-related susceptibility alleles identified significant associations for GAEs at 2q22.3 (rs10496964, P(meta) = 9.1 × 10(-9), OR[T] = 0.68) and at 1q43 for JME (rs12059546, P(meta) = 4.1 × 10(-8), OR[G] = 1.42). Suggestive evidence for an association with GGEs was found in the region 2q24.3 (rs11890028, P(meta) = 4.0 × 10(-6)) nearby the SCN1A gene, which is currently the gene with the largest number of known epilepsy-related mutations. The associated regions harbor high-ranking candidate genes: CHRM3 at 1q43, VRK2 at 2p16.1, ZEB2 at 2q22.3, SCN1A at 2q24.3 and PNPO at 17q21.32. Further replication efforts are necessary to elucidate whether these positional candidate genes contribute to the heritability of the common GGE syndromes.
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Affiliation(s)
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- Institute for Medical Biometry, Informatic and Epidemiology, University of Bonn, Bonn, Germany
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19
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Abstract
Current and emerging technologies for mutation identification are changing the landscape of genetics and accelerating the pace of discovery. Application of high throughput genomic analysis to epilepsy will advance our understanding of the genetic contribution to common forms of epilepsy and suggest novel therapeutic strategies for improved treatment.
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20
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Leu C, de Kovel CGF, Zara F, Striano P, Pezzella M, Robbiano A, Bianchi A, Bisulli F, Coppola A, Giallonardo AT, Beccaria F, Trenité DKN, Lindhout D, Gaus V, Schmitz B, Janz D, Weber YG, Becker F, Lerche H, Kleefuss-Lie AA, Hallman K, Kunz WS, Elger CE, Muhle H, Stephani U, Møller RS, Hjalgrim H, Mullen S, Scheffer IE, Berkovic SF, Everett KV, Gardiner MR, Marini C, Guerrini R, Lehesjoki AE, Siren A, Nabbout R, Baulac S, Leguern E, Serratosa JM, Rosenow F, Feucht M, Unterberger I, Covanis A, Suls A, Weckhuysen S, Kaneva R, Caglayan H, Turkdogan D, Baykan B, Bebek N, Ozbek U, Hempelmann A, Schulz H, Rüschendorf F, Trucks H, Nürnberg P, Avanzini G, Koeleman BPC, Sander T. Genome-wide linkage meta-analysis identifies susceptibility loci at 2q34 and 13q31.3 for genetic generalized epilepsies. Epilepsia 2012; 53:308-18. [PMID: 22242659 DOI: 10.1111/j.1528-1167.2011.03379.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE Genetic generalized epilepsies (GGEs) have a lifetime prevalence of 0.3% with heritability estimates of 80%. A considerable proportion of families with siblings affected by GGEs presumably display an oligogenic inheritance. The present genome-wide linkage meta-analysis aimed to map: (1) susceptibility loci shared by a broad spectrum of GGEs, and (2) seizure type-related genetic factors preferentially predisposing to either typical absence or myoclonic seizures, respectively. METHODS Meta-analysis of three genome-wide linkage datasets was carried out in 379 GGE-multiplex families of European ancestry including 982 relatives with GGEs. To dissect out seizure type-related susceptibility genes, two family subgroups were stratified comprising 235 families with predominantly genetic absence epilepsies (GAEs) and 118 families with an aggregation of juvenile myoclonic epilepsy (JME). To map shared and seizure type-related susceptibility loci, both nonparametric loci (NPL) and parametric linkage analyses were performed for a broad trait model (GGEs) in the entire set of GGE-multiplex families and a narrow trait model (typical absence or myoclonic seizures) in the subgroups of JME and GAE families. KEY FINDINGS For the entire set of 379 GGE-multiplex families, linkage analysis revealed six loci achieving suggestive evidence for linkage at 1p36.22, 3p14.2, 5q34, 13q12.12, 13q31.3, and 19q13.42. The linkage finding at 5q34 was consistently supported by both NPL and parametric linkage results across all three family groups. A genome-wide significant nonparametric logarithm of odds score of 3.43 was obtained at 2q34 in 118 JME families. Significant parametric linkage to 13q31.3 was found in 235 GAE families assuming recessive inheritance (heterogeneity logarithm of odds = 5.02). SIGNIFICANCE Our linkage results support an oligogenic predisposition of familial GGE syndromes. The genetic risk factor at 5q34 confers risk to a broad spectrum of familial GGE syndromes, whereas susceptibility loci at 2q34 and 13q31.3 preferentially predispose to myoclonic seizures or absence seizures, respectively. Phenotype- genotype strategies applying narrow trait definitions in phenotypic homogeneous subgroups of families improve the prospects of disentangling the genetic basis of common familial GGE syndromes.
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21
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Abstract
Epilepsy is one of the most common neurological disorders, with a prevalence of 1% and lifetime incidence of 3%. There are numerous epilepsy syndromes, most of which are considered to be genetic epilepsies. Despite the discovery of more than 20 genes for epilepsy to date, much of the genetic contribution to epilepsy is not yet known. Copy number variants have been established as an important source of mutation in other complex brain disorders, including intellectual disability, autism and schizophrenia. Recent advances in technology now facilitate genome-wide searches for copy number variants and are beginning to be applied to epilepsy. Here, we discuss what is currently known about the contribution of copy number variants to epilepsy, and how that knowledge is redefining classification of clinical and genetic syndromes.
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22
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Crompton DE, Scheffer IE, Taylor I, Cook MJ, McKelvie PA, Vears DF, Lawrence KM, McMahon JM, Grinton BE, McIntosh AM, Berkovic SF. Familial mesial temporal lobe epilepsy: a benign epilepsy syndrome showing complex inheritance. Brain 2010; 133:3221-31. [PMID: 20864493 DOI: 10.1093/brain/awq251] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Temporal lobe epilepsy is the commonest partial epilepsy of adulthood. Although generally perceived as an acquired disorder, several forms of familial temporal lobe epilepsy, with mesial or lateral seizure semiology, have been described. Descriptions of familial mesial temporal lobe epilepsy have varied widely from a benign epilepsy syndrome with prominent déjà vu and without antecedent febrile seizures or magnetic resonance imaging abnormalities, to heterogeneous, but generally more refractory epilepsies, often with a history of febrile seizures and with frequent hippocampal atrophy and high T₂ signal on magnetic resonance imaging. Compelling evidence of a genetic aetiology (rather than chance aggregation) in familial mesial temporal lobe epilepsy has come from twin studies. Dominant inheritance has been reported in two large families, though the usual mode of inheritance is not known. Here, we describe clinical and neurophysiological features of 20 new mesial temporal lobe epilepsy families including 51 affected individuals. The epilepsies in these families were generally benign, and febrile seizure history was infrequent (9.8%). No evidence of hippocampal sclerosis or dysplasia was present on brain imaging. A single individual underwent anterior temporal lobectomy, with subsequent seizure freedom and histopathological evidence of hippocampal sclerosis was not found. Inheritance patterns in probands' relatives were analysed in these families, together with 19 other temporal lobe epilepsy families previously reported by us. Observed frequencies of epilepsies in relatives were lower than predicted by dominant Mendelian models, while only a minority (8/39) of families could be compatible with recessive inheritance. These findings strongly suggest that complex inheritance, similar to that widely accepted in the idiopathic generalized epilepsies, is the usual mode of inheritance in familial mesial temporal lobe epilepsy. This disorder, which appears to be relatively common, and not typically associated with hippocampal sclerosis, is an appropriate target for contemporary approaches to complex disorders such as genome-wide association studies for common genetic variants or deep sequencing for rare variants.
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Affiliation(s)
- Douglas E Crompton
- Department of Medicine and Epilepsy Research Centre, University of Melbourne, Austin Health, West Heidelberg, Victoria, Australia.
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23
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de Kovel CGF, Pinto D, Tauer U, Lorenz S, Muhle H, Leu C, Neubauer BA, Hempelmann A, Callenbach PMC, Scheffer IE, Berkovic SF, Rudolf G, Striano P, Siren A, Baykan B, Sander T, Lindhout D, Kasteleijn-Nolst Trenité DG, Stephani U, Koeleman BPC. Whole-genome linkage scan for epilepsy-related photosensitivity: a mega-analysis. Epilepsy Res 2010; 89:286-94. [PMID: 20153606 DOI: 10.1016/j.eplepsyres.2010.01.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 12/22/2009] [Accepted: 01/23/2010] [Indexed: 10/19/2022]
Abstract
Photoparoxysmal response (PPR) is considered to be a risk factor for idiopathic generalised epilepsy (IGE) and it has a strong genetic basis. Two genome-wide linkage studies have been published before and they identified loci for PPR at 6p21, 7q32, 13q13, 13q31 and 16p13. Here we combine these studies, augmented with additional families, in a mega-analysis of 100 families. Non-parametric linkage analysis identified three suggestive peaks for photosensitivity, two of which are novel (5q35.3 and 8q21.13) and one has been found before (16p13.3). We found no evidence for linkage at four previously detected loci (6p21, 7q32, 13q13 and 13q31). Our results suggest that the different family data sets are not linked to a shared locus. Detailed analysis showed that the peak at 16p13 was mainly supported by a single subset of families, while the peaks at 5q35 and 8q21 had weak support from multiple subsets. Family studies clearly support the role of PPR as a risk factor for IGE. This mega-analysis shows that distinct loci seem to be linked to subsets of PPR-positive families that may differ in subtle clinical phenotypes or geographic origin. Further linkage studies of PPR should therefore include in-depth phenotyping to make appropriate subsets and increase genetic homogeneity.
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Affiliation(s)
- C G F de Kovel
- Complex Genetics Group, Division Biomedical Genetics, University Medical Centre Utrecht, Utrecht, The Netherlands.
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Dibbens LM, Mullen S, Helbig I, Mefford HC, Bayly MA, Bellows S, Leu C, Trucks H, Obermeier T, Wittig M, Franke A, Caglayan H, Yapici Z, Sander T, Eichler EE, Scheffer IE, Mulley JC, Berkovic SF. Familial and sporadic 15q13.3 microdeletions in idiopathic generalized epilepsy: precedent for disorders with complex inheritance. Hum Mol Genet 2009; 18:3626-31. [PMID: 19592580 DOI: 10.1093/hmg/ddp311] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Microdeletion at chromosomal position 15q13.3 has been described in intellectual disability, autism spectrum disorders, schizophrenia and recently in idiopathic generalized epilepsy (IGE). Using independent IGE cohorts, we first aimed to confirm the association of 15q13.3 deletions and IGE. We then set out to determine the relative occurrence of sporadic and familial cases and to examine the likelihood of having seizures for individuals with the microdeletion in familial cases. The 15q13.3 microdeletion was identified in 7 of 539 (1.3%) unrelated cases of IGE using quantitative PCR or SNP arrays and confirmed by array comparative genomic hybridization analysis using probes specific to the 15q13.3 region. The inheritance of this lesion was tracked using family studies. Of the seven microdeletions identified in probands, three were de novo, two were transmitted from an unaffected parent and in two cases the parents were unavailable. Non-penetrance of the microdeletion was identified in 4/7 pedigrees and three pedigrees included other family members with IGE who lacked the 15q13.3 deletion. The odds ratio is 68 (95% confidence interval 29-181), indicating a pathogenic lesion predisposing to epilepsy with complex inheritance and incomplete penetrance for the IGE component of the phenotype in multiplex families.
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Affiliation(s)
- Leanne M Dibbens
- Epilepsy Research Program, SA Pathology at Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia.
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25
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Bai D, Bailey JN, Durón RM, Alonso ME, Medina MT, Martínez-Juárez IE, Suzuki T, Machado-Salas J, Ramos-Ramírez R, Tanaka M, Ortega RHC, López-Ruiz M, Rasmussen A, Ochoa A, Jara-Prado A, Yamakawa K, Delgado-Escueta AV. DNA variants in coding region of EFHC1: SNPs do not associate with juvenile myoclonic epilepsy. Epilepsia 2009; 50:1184-90. [PMID: 18823326 DOI: 10.1111/j.1528-1167.2008.01762.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Juvenile myoclonic epilepsy (JME) accounts for 3 to 12% of all epilepsies. In 2004, we identified a mutation-harboring Mendelian gene that encodes a protein with one EF-hand motif (EFHC1) in chromosome 6p12. We observed one doubly heterozygous and three heterozygous missense mutations in EFHC1 segregating as an autosomal dominant gene with 21 affected members of six Hispanic JME families from California and Mexico. In 2006, similar and three novel missense mutations were reported in sporadic and familial Caucasian JME from Italy and Austria. In this study, we asked if coding single nucleotide polymorphisms (SNPs) of EFHC1 also contribute as susceptibility alleles to JME with complex genetics. METHODS We screened using denaturing high-performance liquid chromatography (DHPLC) and then directly sequenced the 11 exons of EFHC1 in 130 unrelated JME probands, their 352 family members, and seven exons of EFHC1 in 400-614 ethnically matched controls. We carried out case-control association studies between 124 unrelated Hispanic JME probands and 552-614 ethnically matched controls using four SNPs, rs3804506, rs3804505, rs1266787, and rs17851770. We also performed family-based association on SNPs rs3804506 and rs3804505 in 84 complete JME families using the Family-Based Association Test (FBAT) program. RESULTS We found no statistically significant differences between JME probands and controls in case-control association and no genetic transmission disequilibria in family-based association for the tested SNPs. In addition, we identified four new DNA variants in the coding region of EFHC1. CONCLUSION The four coding SNPs, rs3804506, rs3804505, rs1266787, and rs17851770, of EFHC1 may not be susceptibility alleles for JME.
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Affiliation(s)
- Dongsheng Bai
- Epilepsy Genetics/Genomics Lab, CEP, UCLA & VA GLAHS, Los Angeles, California 90073, USA
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26
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Jacobs MP, Leblanc GG, Brooks-Kayal A, Jensen FE, Lowenstein DH, Noebels JL, Spencer DD, Swann JW. Curing epilepsy: progress and future directions. Epilepsy Behav 2009; 14:438-45. [PMID: 19341977 PMCID: PMC2822433 DOI: 10.1016/j.yebeh.2009.02.036] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 02/14/2009] [Indexed: 01/10/2023]
Abstract
During the past decade, substantial progress has been made in delineating clinical features of the epilepsies and the basic mechanisms responsible for these disorders. Eleven human epilepsy genes have been identified and many more are now known from animal models. Candidate targets for cures are now based upon newly identified cellular and molecular mechanisms that underlie epileptogenesis. However, epilepsy is increasingly recognized as a group of heterogeneous syndromes characterized by other conditions that co-exist with seizures. Cognitive, emotional and behavioral co-morbidities are common and offer fruitful areas for study. These advances in understanding mechanisms are being matched by the rapid development of new diagnostic methods and therapeutic approaches. This article reviews these areas of progress and suggests specific goals that once accomplished promise to lead to cures for epilepsy.
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Affiliation(s)
- Margaret P. Jacobs
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Rockville, MD, USA
| | - Gabrielle G. Leblanc
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Rockville, MD, USA
| | - Amy Brooks-Kayal
- Neurology and Pediatrics, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Dan H. Lowenstein
- Department of Neurology, Box 0114, University of California, San Francisco, San Francisco, CA, USA
| | | | - Dennis D. Spencer
- Department of Neurosurgery, Yale University, School of Medicine, New Haven, CT, USA
| | - John W. Swann
- Baylor College of Medicine, Texas Children’s Hospital, Houston, TX, USA
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27
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Mulley JC. Forty Years From Markers to Genes. Twin Res Hum Genet 2008; 11:368-83. [DOI: 10.1375/twin.11.4.368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractThere have been incredible advances made in human genetics over the past 40 years. I have set out in the next few pages to describe just some of these changes and to illustrate how they unfolded through my own experiences.
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29
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Cavalleri GL, Weale ME, Shianna KV, Singh R, Lynch JM, Grinton B, Szoeke C, Murphy K, Kinirons P, O'Rourke D, Ge D, Depondt C, Claeys KG, Pandolfo M, Gumbs C, Walley N, McNamara J, Mulley JC, Linney KN, Sheffield LJ, Radtke RA, Tate SK, Chissoe SL, Gibson RA, Hosford D, Stanton A, Graves TD, Hanna MG, Eriksson K, Kantanen AM, Kalviainen R, O'Brien TJ, Sander JW, Duncan JS, Scheffer IE, Berkovic SF, Wood NW, Doherty CP, Delanty N, Sisodiya SM, Goldstein DB. Multicentre search for genetic susceptibility loci in sporadic epilepsy syndrome and seizure types: a case-control study. Lancet Neurol 2007; 6:970-80. [PMID: 17913586 DOI: 10.1016/s1474-4422(07)70247-8] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND The Epilepsy Genetics (EPIGEN) Consortium was established to undertake genetic mapping analyses with augmented statistical power to detect variants that influence the development and treatment of common forms of epilepsy. METHODS We examined common variations across 279 prime candidate genes in 2717 case and 1118 control samples collected at four independent research centres (in the UK, Ireland, Finland, and Australia). Single nucleotide polymorphism (SNP) and combined set-association analyses were used to examine the contribution of genetic variation in the candidate genes to various forms of epilepsy. FINDINGS We did not identify clear, indisputable common genetic risk factors that contribute to selected epilepsy subphenotypes across multiple populations. Nor did we identify risk factors for the general all-epilepsy phenotype. However, set-association analysis on the most significant p values, assessed under permutation, suggested the contribution of numerous SNPs to disease predisposition in an apparent population-specific manner. Variations in the genes KCNAB1, GABRR2, KCNMB4, SYN2, and ALDH5A1 were most notable. INTERPRETATION The underlying genetic component to sporadic epilepsy is clearly complex. Results suggest that many SNPs contribute to disease predisposition in an apparently population-specific manner. However, subtle differences in phenotyping across cohorts, combined with a poor understanding of how the underlying genetic component to epilepsy aligns with current phenotypic classifications, might also account for apparent population-specific genetic risk factors. Variations across five genes warrant further study in independent cohorts to clarify the tentative association.
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Affiliation(s)
- Gianpiero L Cavalleri
- Department of Clinical Neurological Sciences and Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland Research Institute, and Division of Neurology, Beaumont Hospital, Dublin, Ireland
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Tang B, Sander T, Craven KB, Hempelmann A, Escayg A. Mutation analysis of the hyperpolarization-activated cyclic nucleotide-gated channels HCN1 and HCN2 in idiopathic generalized epilepsy. Neurobiol Dis 2007; 29:59-70. [PMID: 17931874 DOI: 10.1016/j.nbd.2007.08.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Revised: 08/02/2007] [Accepted: 08/06/2007] [Indexed: 12/01/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN1-4) channels play an important role in the regulation of neuronal rhythmicity. In the present study we describe the mutation analysis of HCN1 and HCN2 in 84 unrelated patients with idiopathic generalized epilepsy (IGE). Several functional variants were identified including the amino acid substitution R527Q in HCN2 exon 5. HCN2 channels containing the R527Q variant demonstrated a trend towards a decreased slope of the conductance-voltage relation. We also identified a variant in the splice donor site of HCN2 exon 5 that results in the formation of a cryptic splice donor. In HCN1, the amino acid substitution A881T was identified in one sporadic IGE patient but was not observed in 510 controls. Seven variants were examined further in a case-control association study consisting of a larger cohort of IGE patients. Further studies are warranted to more clearly establish the contribution of HCN1 and HCN2 dysfunction to the genetic variance of common IGE syndromes.
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Affiliation(s)
- Bin Tang
- Department of Human Genetics, Emory University, 615 Michael Street, Whitehead Building, Suite 301, Atlanta, GA 30322, USA
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31
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Sander T, Gaus V. Genetik der idiopathischen Epilepsien. MED GENET-BERLIN 2007. [DOI: 10.1007/s11825-007-0037-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Zusammenfassung
Die idiopathischen Epilepsien sind ätiologisch überwiegend genetisch determiniert und repräsentieren etwa 40% aller Epilepsien. Mutationen in Genen von Ionenkanälen spielen eine zentrale Rolle bei der Pathogenese von eher monogenen Epilepsieformen. Molekulargenetische Forschungsansätze bei den häufigen genetisch komplexen Epilepsien stehen noch am Anfang der Aufklärung der molekularen Mechanismen der Epileptogenese. Erst die umfassende Identifizierung der wichtigsten genetischen Risikofaktoren wird es ermöglichen, verlässliche individuelle Risikoprofile zu erstellen und präventiv ausgerichtete Therapieansätze zu entwickeln.
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Affiliation(s)
- T. Sander
- Aff1_37 grid.6190.e 0000000085803777 Cologne Center for Genomics Universität zu Köln Zülpicher Straße 47 50674 Köln Deutschland
| | - V. Gaus
- Aff2_37 grid.418434.e Neurologische Klinik und Poliklinik Charité – Campus Virchow Klinikum Berlin Deutschland
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Sirén A, Kylliäinen A, Tenhunen M, Hirvonen K, Riita T, Koivikko M. Beneficial effects of antiepileptic medication on absence seizures and cognitive functioning in children. Epilepsy Behav 2007; 11:85-91. [PMID: 17531542 DOI: 10.1016/j.yebeh.2007.04.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 04/08/2007] [Accepted: 04/09/2007] [Indexed: 11/18/2022]
Abstract
In this prospective clinical study, the effects on cognitive functioning of absence seizures, epileptiform EEG discharges, and their abolishment by antiepileptic medication were evaluated in patients newly diagnosed with childhood absence epilepsy or juvenile absence epilepsy. Eleven children in the study group and ten age- and gender-matched controls with mild asthma underwent combined video/EEG and neurocognitive assessment (IQ, fine-motor fluency, attention, visual and spatial memory). The neuropsychological assessment was repeated after the introduction of antiepileptic medication. Ten children with absence epilepsy became clinically seizure free. The study group improved in attention, fine-motor fluency, and visual memory. The controls improved only in fine-motor and attention skills. Duration of generalized 3-Hz spike-wave discharges and clinical absence seizures was negatively correlated with performance on the visual memory task. Cessation of seizures induced by antiepileptic medication may support neurocognitive functioning in children.
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Affiliation(s)
- A Sirén
- Department of Paediatrics, Tampere University Hospital, Tampere, Finland.
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Abstract
One by one, mutation-containing mendelian genes that cause monogenic juvenile myoclonic epilepsies (JME) and single nucleotide polymorphisms (SNP)-susceptibility alleles that increase risks for nonmendelian complex JME should fall to the power of molecular genetics. Of 15 chromosome loci, 3 mendelian genes (alpha1-subunit of the GABA(A) receptor [GABRA1], chloride channel 2 gene [CLCN2], and Myoclonin1/EFHC1) and 2 SNP-susceptibility alleles of putative JME genes in epistases (bromodomain-containing protein 2 [BRD2] and connexin [Cx]-36) have been identified, so far. Antiepileptic drugs now can be designed against the specific molecular defects of JME.
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Affiliation(s)
- Antonio V Delgado-Escueta
- David Geffen School of Medicine, University of California Los Angeles Comprehensive Epilepsy Program, VA Greater Los Angeles Healthcare System West Los Angeles, CA, USA
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34
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Beghi E. Epilepsy. Curr Opin Neurol 2007; 20:169-74. [PMID: 17351487 DOI: 10.1097/wco.0b013e3280d646e4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW To provide a critical review of studies published between December 2005 and November 2006, and detect the advances of basic and clinical research in epilepsy. RECENT FINDINGS The complexity of the mechanisms underlying epileptogenesis and drug resistance was repeatedly highlighted. Seizure diagnosis and classification are still difficult, despite the use of valid and reliable instruments. Even well defined epilepsy syndromes may exhibit complex genetic patterns and atypical electroencephalogram features. Low prevalence rates of active epilepsy have been reported from several countries, suggesting underreporting for sociocultural reasons. Several pregnancy and neonatal factors can be found to increase the risk of epilepsy when accurate data are available from well defined populations. Early remission of seizures does not always predict terminal remission after prolonged follow-up. Cognitive regression may be associated with the presence of interictal electroencephalographic epileptiform abnormalities. A Cochrane review showed lamotrigine to be less frequently withdrawn than carbamazepine. However, these findings are contrasted by clinical practice, which showed no individual drug to be more likely to confer seizure freedom than any other. SUMMARY Recent research highlights the complexity of the mechanisms of epileptogenesis and drug response, and the difficulties with the classification of epilepsy into separate phenotypic categories.
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Affiliation(s)
- Ettore Beghi
- Epilepsy Center, Ospedale San Gerardo, Monza, Italy.
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