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Pulvirenti G, Caccamo M, Lo Bianco M, Mazzurco M, Praticò ER, Giallongo A, Gangi G, Zanghì A, Falsaperla R. Calcium Channels Genes and Their Epilepsy Phenotypes. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1728684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractCalcium (Ca2+) channel gene mutations play an important role in the pathogenesis of neurological episodic disorders like epilepsy. CACNA1A and CACNA1H genes are involved in the synthesis of calcium channels. Mutations in the α1A subunit of the P/Q type voltage-gated calcium channel gene (CACNA1A) located in 19p13.13, which encodes for the transmembrane pore-forming subunit of CAV2.1 voltage-dependent calcium channel, have been correlated to a large clinical spectrum of epilepsy such as idiopathic genetic epilepsy, early infantile epilepsy, and febrile seizures. Moreover, CACNA1A mutations have been demonstrated to be involved in spinocerebellar ataxia type 6, familiar hemiplegic migraine, episodic ataxia type 2, early-onset encephalopathy, and hemiconvulsion–hemiplegia epilepsy syndrome. This wide phenotype heterogeneity associated with CACNA1A mutations is correlated to different clinical and electrophysiological manifestations. CACNA1H gene, located in 16p13.3, encodes the α1H subunit of T-type calcium channel, expressing the transmembrane pore-forming subunit Cav3.2. Despite data still remain controversial, it has been identified as an important gene whose mutations seem strictly related to the pathogenesis of childhood absence epilepsy and other generalized epilepsies. The studied variants are mainly gain-of-function, hence responsible for an increase in neuronal susceptibility to seizures. CACNA1H mutations have also been associated with autism spectrum disorder and other behavior disorders. More recently, also amyotrophic lateral sclerosis has been related to CACNA1H alterations. The aim of this review, other than describe the CACNA1A and CACNA1H gene functions, is to identify mutations reported in literature and to analyze their possible correlations with specific epileptic disorders, purposing to guide an appropriate medical treatment recommendation.
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Affiliation(s)
- Giulio Pulvirenti
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Martina Caccamo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Manuela Lo Bianco
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | | | | | - Alessandro Giallongo
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Gloria Gangi
- Pediatrics Postgraduate Residency Program, Section of Pediatrics and Child Neuropsychiatry, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Antonio Zanghì
- Department of Medical and Surgical Sciences and Advanced Technology “G.F. Ingrassia,” University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics and Pediatric Emergency, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
- Unit of Neonatal Intensive Care and Neonatology, University Hospital “Policlinico Rodolico-San Marco,” Catania, Italy
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Cárdenas-Rodríguez N, Carmona-Aparicio L, Pérez-Lozano DL, Ortega-Cuellar D, Gómez-Manzo S, Ignacio-Mejía I. Genetic variations associated with pharmacoresistant epilepsy (Review). Mol Med Rep 2020; 21:1685-1701. [PMID: 32319641 PMCID: PMC7057824 DOI: 10.3892/mmr.2020.10999] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 01/16/2020] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a common, serious neurological disorder worldwide. Although this disease can be successfully treated in most cases, not all patients respond favorably to medical treatments, which can lead to pharmacoresistant epilepsy. Drug-resistant epilepsy can be caused by a number of mechanisms that may involve environmental and genetic factors, as well as disease- and drug-related factors. In recent years, numerous studies have demonstrated that genetic variation is involved in the drug resistance of epilepsy, especially genetic variations found in drug resistance-related genes, including the voltage-dependent sodium and potassium channels genes, and the metabolizer of endogenous and xenobiotic substances genes. The present review aimed to highlight the genetic variants that are involved in the regulation of drug resistance in epilepsy; a comprehensive understanding of the role of genetic variation in drug resistance will help us develop improved strategies to regulate drug resistance efficiently and determine the pathophysiological processes that underlie this common human neurological disease.
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Affiliation(s)
- Noemí Cárdenas-Rodríguez
- Laboratory of Neuroscience, National Institute of Pediatrics, Ministry of Health, Coyoacán, Mexico City 04530, Mexico
| | - Liliana Carmona-Aparicio
- Laboratory of Neuroscience, National Institute of Pediatrics, Ministry of Health, Coyoacán, Mexico City 04530, Mexico
| | - Diana L Pérez-Lozano
- Laboratory of Neuroscience, National Institute of Pediatrics, Ministry of Health, Coyoacán, Mexico City 04530, Mexico
| | - Daniel Ortega-Cuellar
- Laboratory of Experimental Nutrition, National Institute of Pediatrics, Ministry of Health, Coyoacán, Mexico City 04530, Mexico
| | - Saúl Gómez-Manzo
- Laboratory of Genetic Biochemistry, National Institute of Pediatrics, Ministry of Health, Coyoacán, Mexico City 04530, Mexico
| | - Iván Ignacio-Mejía
- Laboratory of Translational Medicine, Military School of Health Graduates, Lomas de Sotelo, Militar, Mexico City 11200, Mexico
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Downregulation of peripheral PTGS2/COX-2 in response to valproate treatment in patients with epilepsy. Sci Rep 2020; 10:2546. [PMID: 32054883 PMCID: PMC7018850 DOI: 10.1038/s41598-020-59259-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/22/2020] [Indexed: 12/18/2022] Open
Abstract
Antiepileptic drug therapy has significant inter-patient variability in response towards it. The current study aims to understand this variability at the molecular level using microarray-based analysis of peripheral blood gene expression profiles of patients receiving valproate (VA) monotherapy. Only 10 unique genes were found to be differentially expressed in VA responders (n = 15) and 6 genes in the non-responders (n = 8) (fold-change >2, p < 0.05). PTGS2 which encodes cyclooxygenase-2, COX-2, showed downregulation in the responders compared to the non-responders. PTGS2/COX-2 mRNA profiles in the two groups corresponded to their plasma profiles of the COX-2 product, prostaglandin E2 (PGE2). Since COX-2 is believed to regulate P-glycoprotein (P-gp), a multidrug efflux transporter over-expressed at the blood-brain barrier (BBB) in drug-resistant epilepsy, the pathway connecting COX-2 and P-gp was further explored in vitro. Investigation of the effect of VA upon the brain endothelial cells (hCMEC/D3) in hyperexcitatory conditions confirmed suppression of COX-2-dependent P-gp upregulation by VA. Our findings suggest that COX-2 downregulation by VA may suppress seizure-mediated P-gp upregulation at the BBB leading to enhanced drug delivery to the brain in the responders. Our work provides insight into the association of peripheral PTGS2/COX-2 expression with VA efficacy and the role of COX-2 as a potential therapeutic target for developing efficacious antiepileptic treatment.
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Rawat C, Kushwaha S, Srivastava AK, Kukreti R. Peripheral blood gene expression signatures associated with epilepsy and its etiologic classification. Genomics 2020; 112:218-224. [DOI: 10.1016/j.ygeno.2019.01.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/23/2019] [Accepted: 01/26/2019] [Indexed: 01/19/2023]
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ABCB1 Polymorphisms and Drug-Resistant Epilepsy in a Tunisian Population. DISEASE MARKERS 2019; 2019:1343650. [PMID: 31871496 PMCID: PMC6913308 DOI: 10.1155/2019/1343650] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 10/26/2019] [Indexed: 12/13/2022]
Abstract
Background Epilepsy is one of the most common neurological disorders with about 30% treatment failure rate. An interindividual variations in efficacy of antiepileptic drugs (AEDs) make the treatment of epilepsy challenging, which can be attributed to genetic factors such as ATP-Binding Cassette sub-family B, member1 (ABCB1) gene polymorphisms. Objective The main objective of the present study is to evaluate the association of ABCB1 C1236T, G2677T, and C3435T polymorphisms with treatment response among Tunisian epileptic patients. Materials and Methods One hundred epileptic patients, originated from north of Tunisia, were recruited and categorized into 50 drug-resistant and 50 drug-responsive patients treated with antiepileptic drugs (AEDs) as per the International League Against Epilepsy. DNA of patients was extracted and ABCB1 gene polymorphisms studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results The C1236T, G2677T, and C3435T polymorphisms were involved into AED resistance. Significant genotypic (C1236T TT (p ≤ 0.001); G2677T TT (p = 0.001); C3435T TT (p ≤ 0.001)) and allelic associations (C1236T T (3.650, p ≤ 0.001); G2677TT (1.801, p = 0.044); C3435T T (4.730, p ≤ 0.001)) with drug resistance epilepsy (DRE) were observed. A significant level of linkage disequilibrium (LD) was also noted between ABCB1 polymorphisms. Patients with the haplotypes CT and TT (C1236T-G2677T); GT, TC, and TT (G2677T-C3435T); CT and TT (C1236T-C3435T); CTT, TTC, TGT, and TTT (C1236T-G2677T-C3435T) were also significantly associated to AED resistance. Conclusions The response to antiepileptics seems to be modulated by TT genotypes, T alleles, and the predicted haplotypes for the tested SNPs in our population. Genetic analysis is a valuable tool for predicting treatment response and thus will contribute to personalized medicine for Tunisian epileptic patients.
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Ajmi M, Boujaafar S, Zouari N, Amor D, Nasr A, Rejeb NB, Amor SB, Omezzine A, Benammou S, Bouslama A. Association between ABCB1 polymorphisms and response to first-generation antiepileptic drugs in a Tunisian epileptic population. Int J Neurosci 2017; 128:705-714. [DOI: 10.1080/00207454.2017.1412964] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Marwa Ajmi
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
- Higher Institute of Biotechnology of Monastir, University of Monastir, Monastir, Tunisia
| | - Sana Boujaafar
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
| | - Nadia Zouari
- Neurology Department, Sahloul University Hospital, Sousse, Tunisia
| | - Dorra Amor
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
| | - Asma Nasr
- Neurology Department, Sahloul University Hospital, Sousse, Tunisia
| | - Nabila Ben Rejeb
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
- Faculty of Pharmacy, University of Monastir, Monastir, Tunisia
| | - Sana Ben Amor
- Neurology Department, Sahloul University Hospital, Sousse, Tunisia
| | - Asma Omezzine
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
- Faculty of Pharmacy, University of Monastir, Monastir, Tunisia
| | - Sofien Benammou
- Neurology Department, Sahloul University Hospital, Sousse, Tunisia
| | - Ali Bouslama
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
- Biochemistry Department, Sahloul University Hospital, Sousse, Tunisia
- Faculty of Pharmacy, University of Monastir, Monastir, Tunisia
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dos Santos BP, Marinho CRM, Marques TEBS, Angelo LKG, Malta MVDS, Duzzioni M, de Castro OW, Leite JP, Barbosa FT, Gitaí DLG. Genetic susceptibility in Juvenile Myoclonic Epilepsy: Systematic review of genetic association studies. PLoS One 2017; 12:e0179629. [PMID: 28636645 PMCID: PMC5479548 DOI: 10.1371/journal.pone.0179629] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 06/01/2017] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Several genetic association investigations have been performed over the last three decades to identify variants underlying Juvenile Myoclonic Epilepsy (JME). Here, we evaluate the accumulating findings and provide an updated perspective of these studies. METHODOLOGY A systematic literature search was conducted using the PubMed, Embase, Scopus, Lilacs, epiGAD, Google Scholar and Sigle up to February 12, 2016. The quality of the included studies was assessed by a score and classified as low and high quality. Beyond outcome measures, information was extracted on the setting for each study, characteristics of population samples and polymorphisms. RESULTS Fifty studies met eligibility criteria and were used for data extraction. With a single exception, all studies used a candidate gene approach, providing data on 229 polymorphisms in or near 55 different genes. Of variants investigating in independent data sets, only rs2029461 SNP in GRM4, rs3743123 in CX36 and rs3918149 in BRD2 showed a significant association with JME in at least two different background populations. The lack of consistent associations might be due to variations in experimental design and/or limitations of the approach. CONCLUSIONS Thus, despite intense research evidence established, specific genetic variants in JME susceptibility remain inconclusive. We discussed several issues that may compromise the quality of the results, including methodological bias, endophenotype and potential involvement of epigenetic factors. PROSPERO REGISTRATION NUMBER CRD42016036063.
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Affiliation(s)
- Bruna Priscila dos Santos
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | - Chiara Rachel Maciel Marinho
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | | | - Layanne Kelly Gomes Angelo
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | - Maísa Vieira da Silva Malta
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | - Marcelo Duzzioni
- Department of Pharmacology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | - Olagide Wagner de Castro
- Department of Physiology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | - João Pereira Leite
- Division of Neurology, Department of Neurosciences and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - Daniel Leite Góes Gitaí
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
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Oprisan B, Stoica I, Avadanei MI. Morphological changes induced in erythrocyte membrane by the antiepileptic treatment: An atomic force microscopy study. Microsc Res Tech 2016; 80:364-373. [DOI: 10.1002/jemt.22804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 10/04/2016] [Accepted: 10/22/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Bogdan Oprisan
- Faculty of Medicine, Discipline Biophysics and Medical Physics; “Grigore T. Popa” University of Medicine and Pharmacy; Iasi Romania
| | - Iuliana Stoica
- Department of Polymer Materials Physics; “Petru Poni” Institute of Macromolecular Chemistry; Iasi Romania
| | - Mihaela Iuliana Avadanei
- Department of Polymer Materials Physics; “Petru Poni” Institute of Macromolecular Chemistry; Iasi Romania
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Baghel R, Grover S, Kaur H, Jajodia A, Parween S, Sinha J, Srivastava A, Srivastava AK, Bala K, Chandna P, Kushwaha S, Agarwal R, Kukreti R. Synergistic association of STX1A and VAMP2 with cryptogenic epilepsy in North Indian population. Brain Behav 2016; 6:e00490. [PMID: 27458546 PMCID: PMC4951625 DOI: 10.1002/brb3.490] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 03/05/2016] [Accepted: 03/29/2016] [Indexed: 12/18/2022] Open
Abstract
INTRODUCTION "Common epilepsies", merely explored for genetics are the most frequent, nonfamilial, sporadic cases in hospitals. Because of their much debated molecular pathology, there is a need to focus on other neuronal pathways including the existing ion channels. METHODS For this study, a total of 214 epilepsy cases of North Indian ethnicity comprising 59.81% generalized, 40.19% focal seizures, and based on epilepsy types, 17.29% idiopathic, 37.38% cryptogenic, and 45.33% symptomatic were enrolled. Additionally, 170 unrelated healthy individuals were also enrolled. Here, we hypothesize the involvement of epilepsy pathophysiology genes, that is, synaptic vesicle cycle, SVC genes (presynapse), ion channels and their functionally related genes (postsynapse). An interactive analysis was initially performed in SVC genes using multifactor dimensionality reduction (MDR). Further, in order to understand the influence of ion channels and their functionally related genes, their interaction analysis with SVC genes was also performed. RESULTS A significant interactive two-locus model of STX1A_rs4363087|VAMP2_rs2278637 (presynaptic genes) was observed among SVC variants in all epilepsy cases (P 1000-value = 0.054; CVC = 9/10; OR = 2.86, 95%CI = 1.88-4.35). Further, subgroup analysis revealed stronger interaction for the same model in cryptogenic epilepsy patients only (P 1000-value = 0.012; CVC = 10/10; OR = 4.59, 95%CI = 2.57-8.22). However, interactive analysis of presynaptic and postsynaptic genes did not show any significant association. CONCLUSIONS Significant synergistic interaction of SVC genes revealed the possible functional relatedness of presynapse with pathophysiology of cryptogenic epilepsy. Further, to establish the clinical utility of the results, replication in a large and similar phenotypic group of patients is warranted.
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Affiliation(s)
- Ruchi Baghel
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India
| | - Sandeep Grover
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India; Division of Pneumonology-Immunology Department of Paediatrics Charité University Medical Centre Berlin Germany
| | - Harpreet Kaur
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India
| | - Ajay Jajodia
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India
| | - Shama Parween
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India
| | - Juhi Sinha
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India
| | - Ankit Srivastava
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India
| | - Achal Kumar Srivastava
- Neurology Department Neuroscience Centre All India Institute of Medical Sciences (AIIMS) New Delhi India
| | - Kiran Bala
- Institute of Human Behavior & Allied Sciences (IHBAS) Dilshad Garden Delhi 110 095 India
| | | | - Suman Kushwaha
- Institute of Human Behavior & Allied Sciences (IHBAS) Dilshad Garden Delhi 110 095 India
| | - Rachna Agarwal
- Institute of Human Behavior & Allied Sciences (IHBAS) Dilshad Garden Delhi 110 095 India
| | - Ritushree Kukreti
- Council of Scientific and Industrial Research (CSIR) Institute of Genomics and Integrative Biology (IGIB) Mall Road Delhi 110 007 India
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Whelan CD, Alhusaini S, O'Hanlon E, Cheung M, Iyer PM, Meaney JF, Fagan AJ, Boyle G, Delanty N, Doherty CP, Cavalleri GL. White matter alterations in patients with MRI-negative temporal lobe epilepsy and their asymptomatic siblings. Epilepsia 2015; 56:1551-61. [DOI: 10.1111/epi.13103] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2015] [Indexed: 12/27/2022]
Affiliation(s)
- Christopher D. Whelan
- Molecular and Cellular Therapeutics Department; Royal College of Surgeons in Ireland; Dublin Ireland
- Imaging Genetics Center; Mark and Mary Stevens Neuroimaging and Informatics Institute; University of Southern California; Los Angeles California U.S.A
| | - Saud Alhusaini
- Molecular and Cellular Therapeutics Department; Royal College of Surgeons in Ireland; Dublin Ireland
| | - Erik O'Hanlon
- Department of Psychiatry; Royal College of Surgeons in Ireland; Dublin 2 Ireland
| | - Maria Cheung
- Molecular and Cellular Therapeutics Department; Royal College of Surgeons in Ireland; Dublin Ireland
| | | | - James F. Meaney
- Centre for Advanced Medical Imaging (CAMI); St. James's Hospital; Dublin Ireland
| | - Andrew J. Fagan
- Centre for Advanced Medical Imaging (CAMI); St. James's Hospital; Dublin Ireland
| | - Gerard Boyle
- Centre for Advanced Medical Imaging (CAMI); St. James's Hospital; Dublin Ireland
| | - Norman Delanty
- Molecular and Cellular Therapeutics Department; Royal College of Surgeons in Ireland; Dublin Ireland
- Division of Neurology; Beaumont Hospital; Dublin Ireland
| | | | - Gianpiero L. Cavalleri
- Molecular and Cellular Therapeutics Department; Royal College of Surgeons in Ireland; Dublin Ireland
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Klein KM, Berkovic SF. Genetics of vasovagal syncope. Auton Neurosci 2014; 184:60-5. [DOI: 10.1016/j.autneu.2014.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 03/26/2014] [Indexed: 12/01/2022]
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Mantis JG, Meidenbauer JJ, Zimick NC, Centeno NA, Seyfried TN. Glucose reduces the anticonvulsant effects of the ketogenic diet in EL mice. Epilepsy Res 2014; 108:1137-44. [PMID: 24938543 DOI: 10.1016/j.eplepsyres.2014.05.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 03/14/2014] [Accepted: 05/19/2014] [Indexed: 01/24/2023]
Abstract
The ketogenic diet (KD) is known to be anticonvulsant and anti-epileptogenic. While the mechanism behind this therapeutic benefit is unclear, a reduction of circulating glucose levels through calorie restriction (CR) has been implicated. Foods or drinks that elevate blood glucose are known to compromise the therapeutic benefit of the KD in some children with epilepsy. We therefore evaluated the effect of a calorie restricted KD (KD-R) with supplementation of glucose in the drinking water of EL mice, a natural model of idiopathic generalized epilepsy, prior to seizure testing to assess the effect of glucose on seizure generation. Mice were fed either a standard diet or the KD unrestricted (SD-UR and KD-UR, respectively), or the KD restricted (KD-R). d-Glucose (25 mM) was supplemented in the drinking water of KD-R fed mice for 0.5h or for 2.5h prior to seizure testing. Each restricted mouse served as its own body weight control to achieve a 15-18% body weight reduction. Seizure susceptibility, body weights, and plasma glucose and β-hydroxybutyrate levels were measured over a nine-week treatment period. Body weights and glucose levels remained high over the testing period in both the SD-UR and the KD-UR groups, but were significantly reduced in all R-fed groups. A significant increase in β-hydroxybutyrate levels was observed in all KD groups. Seizure susceptibility remained highest in the SD-UR group, was slightly reduced in the KD-UR group, and was significantly reduced after three weeks in all R-fed groups. Supplementation of glucose prior to seizure testing resulted in a decrease of seizure threshold for R-fed mice, but did not alter bodyweight or circulating glucose levels. The KD has both an anticonvulsant and antiepileptogenic effect in EL mice. Here we confirm that CR enhances the anticonvulsant action of the KD in EL mice. Additionally, we show for the first time that supplementation of glucose decreases the anticonvulsant action of the KD, which further supports the hypothesis that CR works through transitioning metabolism from glucose to ketone utilization for energy.
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Affiliation(s)
- John G Mantis
- Biology Department, Boston College, Chestnut Hill, MA, USA
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Baghel R, Jajodia A, Grover S, Kukreti R. Research Highlights: Highlights from the latest articles focusing on a new gene set for better drug response prediction of epilepsy patients. Pharmacogenomics 2014; 15:581-6. [DOI: 10.2217/pgs.14.11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Ruchi Baghel
- Genomics & Molecular Medicine Unit, Institute of Genomics & Integrative Biology (IGIB), Council of Scientific & Industrial Research (CSIR), Mall Road, Delhi 110 007, India
| | - Ajay Jajodia
- Genomics & Molecular Medicine Unit, Institute of Genomics & Integrative Biology (IGIB), Council of Scientific & Industrial Research (CSIR), Mall Road, Delhi 110 007, India
| | - Sandeep Grover
- Genomics & Molecular Medicine Unit, Institute of Genomics & Integrative Biology (IGIB), Council of Scientific & Industrial Research (CSIR), Mall Road, Delhi 110 007, India
| | - Ritushree Kukreti
- Genomics & Molecular Medicine Unit, Institute of Genomics & Integrative Biology (IGIB), Council of Scientific & Industrial Research (CSIR), Mall Road, Delhi 110 007, India
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Salah ON, Abdelraouf ER, Abdelhameed MH, Dawood AA, Hashish AF, Kilany A, Helal SI. Assessment of the Level of GABA and Some Trace Elements in Blood in Children who Suffer from Familial Febrile Convulsions. Open Access Maced J Med Sci 2014. [DOI: 10.3889/oamjms.2014.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Febrile seizure is one of the most common neurological problems during childhood. The etiology and pathogenesis of febrile seizure remain unknown. However, several factors such as vitamin B6 deficiency, electrolyte disturbances, and reduction in serum zinc, selenium, magnesium levels, and low gamma - aminobutyric acid (GABA) levels are thought to play a role in the pathogenesis of febrile seizure. The present study included twenty children from 10 families, 11 were male and 9 were female. Each family has at least 2 members with a history of febrile convulsion. All cases were subjected to the following: Determination of serum levels of copper, zinc, magnesium, selenium level in serum, and plasma level of γ-aminobytaric acid (GABA). Serum levels of selenium and GABA were statistically significantly low in comparison with controls. Serum copper was statistically significantly higher in cases than controls, while serum zinc showed no significant changes in the cases of febrile convulsion compared with the control group. The mean Zn level in the serum of febrile convulsion was found to be at lower level than in the control group. The serum magnesium was significantly low in cases than controls. The logistic regression model in our study shows that Selenium and Magnesium have protective effects, while Copper has causative effect.
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Ferraro TN. The relationship between genes affecting the development of epilepsy and approaches to epilepsy therapy. Expert Rev Neurother 2014; 14:329-52. [DOI: 10.1586/14737175.2014.888651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Eckle VS, Shcheglovitov A, Vitko I, Dey D, Yap CC, Winckler B, Perez-Reyes E. Mechanisms by which a CACNA1H mutation in epilepsy patients increases seizure susceptibility. J Physiol 2013; 592:795-809. [PMID: 24277868 DOI: 10.1113/jphysiol.2013.264176] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
T-type calcium channels play essential roles in regulating neuronal excitability and network oscillations in the brain. Mutations in the gene encoding Cav3.2 T-type Ca(2+) channels, CACNA1H, have been found in association with various forms of idiopathic generalized epilepsy. We and others have found that these mutations may influence neuronal excitability either by altering the biophysical properties of the channels or by increasing their surface expression. The goals of the present study were to investigate the excitability of neurons expressing Cav3.2 with the epilepsy mutation, C456S, and to elucidate the mechanisms by which it influences neuronal properties. We found that expression of the recombinant C456S channels substantially increased the excitability of cultured neurons by increasing the spontaneous firing rate and reducing the threshold for rebound burst firing. Additionally, we found that molecular determinants in the I-II loop (the region in which most childhood absence epilepsy-associated mutations are found) substantially increase the surface expression of T-channels but do not alter the relative distribution of channels into dendrites of cultured hippocampal neurons. Finally, we discovered that expression of C456S channels promoted dendritic growth and arborization. These effects were reversed to normal by either the absence epilepsy drug ethosuximide or a novel T-channel blocker, TTA-P2. As Ca(2+)-regulated transcription factors also increase dendritic development, we tested a transactivator trap assay and found that the C456S variant can induce changes in gene transcription. Taken together, our findings suggest that gain-of-function mutations in Cav3.2 T-type Ca(2+) channels increase seizure susceptibility by directly altering neuronal electrical properties and indirectly by changing gene expression.
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Affiliation(s)
- Veit-Simon Eckle
- Jordan Hall 800735, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA.
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17
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GABRG2, rs211037 is associated with epilepsy susceptibility, but not with antiepileptic drug resistance and febrile seizures. Pharmacogenet Genomics 2013; 23:605-10. [DOI: 10.1097/fpc.0000000000000000] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Manna I, Labate A, Mumoli L, Ferlazzo E, Aguglia U, Quattrone A, Gambardella A. Failure to confirm association of a polymorphism in KCNMB4 gene with mesial temporal lobe epilepsy. Epilepsy Res 2013; 106:284-7. [DOI: 10.1016/j.eplepsyres.2013.03.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/08/2013] [Accepted: 03/28/2013] [Indexed: 01/26/2023]
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Bakir-Gungor B, Baykan B, Ugur İseri S, Tuncer FN, Sezerman OU. Identifying SNP targeted pathways in partial epilepsies with genome-wide association study data. Epilepsy Res 2013; 105:92-102. [PMID: 23498093 DOI: 10.1016/j.eplepsyres.2013.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 01/15/2013] [Accepted: 02/13/2013] [Indexed: 12/18/2022]
Abstract
PURPOSE In a recent genome-wide association study for partial epilepsies in the European population, a common genetic variation has been reported to affect partial epilepsy only modestly. However, in complex diseases such as partial epilepsy, multiple factors (e.g. single nucleotide polymorphisms, microRNAs, metabolic and epigenetic factors) may target different sets of genes in the same pathway, affecting its function and thus causing the disease development. In this regard, we hypothesize that the pathways are critical for elucidating the mechanisms underlying partial epilepsy. METHODS Previously we had developed a novel methodology with the aim of identifying the disease-related pathways. We had combined evidence of genetic association with current knowledge of (i) biochemical pathways, (ii) protein-protein interaction networks, and (iii) the functional information of selected single nucleotide polymorphisms. In our present study, we apply this methodology to a data set on partial epilepsy, including 3445 cases and 6935 controls of European ancestry. RESULTS We have identified 30 overrepresented pathways with corrected p-values smaller than 10(-12). These pathways include complement and coagulation cascades, cell cycle, focal adhesion, extra cellular matrix-receptor interaction, JAK-STAT signaling pathway, MAPK signaling pathway, proteasome, ribosome, calcium signaling and regulation of actin cytoskeleton pathways. Most of these pathways have growing scientific support in the literature as being associated with partial epilepsy. We also demonstrate that different factors affect distinct parts of the pathways, as shown here on complement and coagulation cascades pathway with a comparison of gene expression vs. genome-wide association study. CONCLUSIONS Traditional studies on genome-wide association have not revealed strong associations in epilepsies, since these single nucleotide polymorphisms are not shared by most of the patients. Our results suggest that it is more effective to incorporate the functional effect of a single nucleotide polymorphism on the gene product, protein-protein interaction networks and functional enrichment tools into genome-wide association studies. These can then be used to determine leading molecular pathways, which cannot be detected through traditional analyses. We hope that this type of analysis brings the research community one step closer to unraveling the complex genetic structure of epilepsies.
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Affiliation(s)
- B Bakir-Gungor
- Department of Genetics and Bioinformatics, Faculty of Arts and Sciences, Bahcesehir University, Ciragan Cad. Osmanpasa Mektebi Sok., No.: 4, 34353, Besiktas, Istanbul, Turkey.
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Aljasir B, Ioannidis JPA, Yurkiewich A, Moher D, Higgins JPT, Arora P, Little J. Assessment of systematic effects of methodological characteristics on candidate genetic associations. Hum Genet 2013; 132:167-78. [PMID: 23095857 DOI: 10.1007/s00439-012-1237-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 10/08/2012] [Indexed: 12/30/2022]
Abstract
Candidate genetic association studies have been found to have a low replication rate in the past. Here, we aimed to assess whether aspects of reported methodological characteristics in genetic association studies may be related to the magnitude of effects observed. An observational, literature-based investigation of 511 case-control studies of genetic association studies indexed in 2007, was undertaken. Meta-regression analyses were used to assess the relationship between 23 reported methodological characteristics and the magnitude of genetic associations. The 511 studies had been conducted in 52 countries and were published in 220 journals (median impact factor 5.1). The multivariate meta-regression model of methodological characteristics plus disease category accounted for 17.2 % of the between-study variance in the magnitude of the reported genetic associations. Our findings are consistent with the view that better conducted and better reported genetic association research may lead to less inflated results.
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Affiliation(s)
- Badr Aljasir
- Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada
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21
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GABRG2 rs211037 polymorphism and epilepsy: A systematic review and meta-analysis. Seizure 2013; 22:53-8. [DOI: 10.1016/j.seizure.2012.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 10/14/2012] [Accepted: 10/15/2012] [Indexed: 11/20/2022] Open
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22
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Scanlon C, Ronan L, Doherty CP, Cavalleri GL, Tirupati S, Alhusaini S, Maguire S, Delanty N, Iyer PM, Chaila E, Fitzsimons M. MRI-based brain structure volumes in temporal lobe epilepsy patients and their unaffected siblings: a preliminary study. J Neuroimaging 2012; 23:64-70. [PMID: 22928655 DOI: 10.1111/j.1552-6569.2012.00736.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
INTRODUCTION Investigating the heritability of brain structure may be useful in simplifying complicated genetic studies in temporal lobe epilepsy (TLE). A preliminary study is presented to determine if volume deficits of candidate brain structures present at a higher rate in unaffected siblings than controls subjects. METHODS T1-weighted MR images was acquired for 28 TLE patients, a same-sex unaffected sibling of 12 of these and 28 normal controls. Selected brain structure volumes were measured using an automated whole brain segmentation technique. Candidate brain structure endophenotypes were determined and group differences were investigated between (1) controls and patients and (2) controls and siblings. ICC's were used to measure the quantitative volumetric association within each sibling pair. RESULTS TLE patients demonstrated a significantly lower cerebral white matter, bilateral hippocampus, thalamus, and left entorhinal cortex volumes when compared with controls. A significant deficit in cerebral white matter (CWM) was common to patient and nonaffected siblings when compared with controls. Furthermore, a significant correlation was revealed between patients and siblings in CWM and bilateral thalamus. CONCLUSION The findings suggest an overlap in the neurodevelopmental genes responsible for both brain structure and the expression of the disease. Further work is ongoing to confirm these findings.
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Affiliation(s)
- Cathy Scanlon
- Brain Morphometry Laboratory, Epilepsy Programme, Beaumont Hospital, Dublin, Ireland
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23
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Czyz W, Morahan JM, Ebers GC, Ramagopalan SV. Genetic, environmental and stochastic factors in monozygotic twin discordance with a focus on epigenetic differences. BMC Med 2012; 10:93. [PMID: 22898292 PMCID: PMC3566971 DOI: 10.1186/1741-7015-10-93] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 08/17/2012] [Indexed: 03/16/2023] Open
Abstract
Genetic-epidemiological studies on monozygotic (MZ) twins have been used for decades to tease out the relative contributions of genes and the environment to a trait. Phenotypic discordance in MZ twins has traditionally been ascribed to non-shared environmental factors acting after birth, however recent data indicate that this explanation is far too simple. In this paper, we review other reasons for discordance, including differences in the in utero environment, genetic mosaicism, and stochastic factors, focusing particularly on epigenetic discordance. Epigenetic differences are gaining increasing recognition. Although it is clear that in specific cases epigenetic alterations provide a causal factor in disease etiology, the overall significance of epigenetics in twin discordance remains unclear. It is also challenging to determine the causality and relative contributions of environmental, genetic, and stochastic factors to epigenetic variability. Epigenomic profiling studies have recently shed more light on the dynamics of temporal methylation change and methylome heritability, yet have not given a definite answer regarding their relevance to disease, because of limitations in establishing causality. Here, we explore the subject of epigenetics as another component in human phenotypic variability and its links to disease focusing particularly on evidence from MZ twin studies.
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Affiliation(s)
- Witold Czyz
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
| | - Julia M Morahan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
| | - George C Ebers
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
| | - Sreeram V Ramagopalan
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences (Clinical Neurology), University of Oxford, Oxford, UK
- Blizard Institute, Queen Mary University of London, Barts and The London School of Medicine and Dentistry, London, UK
- London School of Hygiene and Tropical Medicine, London, UK
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Ferraro TN. Discovery of epilepsy susceptibility genes: implications for therapy development and pharmacogenomics. Pharmacogenomics 2012; 13:731-4. [DOI: 10.2217/pgs.12.31] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Thomas N Ferraro
- Center for Neurobiology & Behavior, Departments of Psychiatry & Pharmacology, Perelman School of Medicine, University of Pennsylvania, PA 19104, USA
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25
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Genetics of temporal lobe epilepsy: a review. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:863702. [PMID: 22957248 PMCID: PMC3420533 DOI: 10.1155/2012/863702] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 11/06/2011] [Accepted: 12/07/2011] [Indexed: 11/18/2022]
Abstract
Temporal lobe epilepsy (TLE) is usually regarded as a polygenic and complex disorder. To understand its genetic component, numerous linkage analyses of familial forms and association studies of cases versus controls have been conducted since the middle of the nineties. The present paper lists genetic findings for TLE from the initial segregation analysis to the most recent results published in May 2011. To date, no genes have been clearly related to TLE despite many efforts to do so. However, it is vital to continue replication studies and collaborative attempts to find significant results and thus determine which gene variant combination plays a definitive role in the aetiology of TLE.
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Khoshdel A, Kheiri S, Habibian R, Nozari A, Baradaran A. Lack of association between TNF-α gene polymorphisms at position -308 A, -850T and risk of simple febrile convulsion in pediatric patients. Adv Biomed Res 2012; 1:85. [PMID: 23946933 PMCID: PMC3724328 DOI: 10.4103/2277-9175.105167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 03/15/2012] [Indexed: 11/17/2022] Open
Abstract
Background: Febrile convulsions (FCs), occurring between 6 months and 6 years of age is the most common seizure disorder during childhood. The febrile response is thought to be mediated by the release of pyrogenic cytokines, such as tumor necrosis factor and interleukin-1 (IL-1). There is a significant relationship between genetic components for susceptibility of FCs and different report mutation. We investigated association between two polymorphisms in the tumor necrosis factor (TNF)-α promoter region (G-308A, C-850T) and FCs in the southwest area of Iran. Materials and Methods: In this matched case–control study, 100 patients with febrile convulsion as case group and 130 healthy children as control group were enrolled in the study. Peripheral blood samples were collected and DNA was extracted by standard phenol–chloroform method. The genotype and allele frequencies of TNF- α polymorphisms in case and control groups were determined by using PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism) method. Statistical analysis was done using Chi-square test. Results: The average age of case and control groups were 3.4 ± 1.4 and 3.4 ± 1.2 years, respectively. There was no significant difference between age and sex in both the groups (P > 0.05). A family history of febrile convulsion was detected in 44% of patients. Moreover, the simple febrile convulsion was detected in 85% of the case group. Conclusion: RFLP analysis of TNF- α promoter region polymorphisms, considering P = 0.146 and P = 0.084 for G-308A and C-850T, respectively, showed no correlation between TNF- α polymorphisms and predisposition to simple febrile, based on the kind of convulsion (atypical and simple febrile convulsion). We found a significant relation between genotype distribution of G-308A and atypical febrile convulsion in case group (P = 0.04). A significant correlation between genotype distribution of G-308A and atypical febrile convulsion in the case group was found, but there was no correlation between TNF- α polymorphisms at positions of -308A, and 850T and predisposition to simple febrile convulsion. Further studies are needed to understand clinical usefulness of this correlation.
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Affiliation(s)
- Abolfazl Khoshdel
- Department of pediatric, Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran
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27
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Poza JJ. The genetics of focal epilepsies. HANDBOOK OF CLINICAL NEUROLOGY 2012; 107:153-161. [PMID: 22938969 DOI: 10.1016/b978-0-444-52898-8.00009-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Juan José Poza
- Department of Neurology, Hospital Donostia, San Sebastian, Spain.
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28
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Cavalleri GL, Delanty N. Opportunities and challenges for genome sequencing in the clinic. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012; 89:65-83. [PMID: 23046882 DOI: 10.1016/b978-0-12-394287-6.00003-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Human genome sequencing technology is developing rapidly. These developments are providing exciting opportunities for genetic mapping of human traits, ranging from accelerated discovery of mutations underlying relatively simple Mendelian disorders to more genetically complex human diseases. This chapter outlines the development of whole-genome sequencing in a historical context of genetic mapping and explores the impact that sequencing is having on gene discovery study design. Using the example of epilepsy, the authors outline the opportunities and barriers for the translation of genetic predictors from discovery to the clinic. Finally, the authors discuss the practical challenges of actual implementation of whole-genome sequencing to the clinic.
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Affiliation(s)
- Gianpiero L Cavalleri
- Molecular and Cellular Therapeutics, The Royal College of Surgeons in Ireland, Dublin, Ireland.
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A genetic epidemiological survey of idiopathic epilepsy in the Chinese Han population. Epilepsy Res 2011; 98:199-205. [PMID: 21993360 DOI: 10.1016/j.eplepsyres.2011.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 09/20/2011] [Accepted: 09/20/2011] [Indexed: 11/20/2022]
Abstract
BACKGROUND Idiopathic epilepsy (IE) is a syndrome that comprises epilepsy only, with no underlying structural brain lesion or other neurological signs or symptoms. Numerous studies have shown that genetic factors play an important role in IE. IE is a common disease in the Chinese Han population. However, the genetic epidemiological characteristics of IE in the Chinese population, such as its heritability and genetic models remain unclear. PURPOSE To study the clinical and epidemiological profile of IE, to estimate the heritability and determine the possible genetic models for IE in the Chinese Han population. METHODS A case-control family-based study was carried out in a rural Chinese county. We collected data from eligible IE patients, controls, and their relatives by a uniform structured questionnaire, and then established an epidemiologic database of epilepsy using Access2010. General statistical and genetic epidemiological analyses (Falconer's-method-based heritability, simple segregation ratio and complex segregation analysis) were performed using SAS9.1 and the SAGE-SEGREG program. RESULTS (1) The prevalence of IE among the relatives of probands with IE (2.75‰) was higher than that among the relatives of the control group (0.61‰). The prevalence of IE among the first-, second-, and third-degree relatives of the probands with IE was 11.45‰, 2.64‰ and 0.98‰, respectively, which were all higher than the corresponding prevalences in the relatives of controls. Trend-chi-squared tests indicated that the prevalence of epilepsy increased among the relatives of probands with decreasing kinship distance (χ(2)=97.16, P=0.00). (2) The heritability of IE among first-, second-, and third-degree relatives was 55.06%, 50.72% and 16.98%, respectively. The weighted mean heritability was 46.07%. (3) The simple segregation ratio of IE was 0.03, significantly lower than the Mendelian recessive segregation ratio of 0.25. Complex segregation analysis showed that the population we studied accepted a Mendelian genetic model (dominant, recessive, additive, and a major gene model) and excluded the general model, non-transmitted model, and environment-only model. A Mendelian additive inheritance model was ultimately the best-fit because it had the lowest Akaike Information Criteria score. CONCLUSION In the Chinese Han population, IE follows a pattern of polygenic Mendelian additive inheritance rather than single-gene inheritance. Nearly half of the total variance can be explained by genetic factors.
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Cavalleri GL, McCormack M, Alhusaini S, Chaila E, Delanty N. Pharmacogenomics and epilepsy: the road ahead. Pharmacogenomics 2011; 12:1429-47. [DOI: 10.2217/pgs.11.85] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Epilepsy is one of the most common, serious neurological disorders, affecting an estimated 50 million people worldwide. The condition is typically treated using antiepileptic drugs of which there are 16 in widespread use. However, there are many different syndrome and seizure types within epilepsy and information guiding clinicians on the most effective drug and dose for individual patients is lacking. Further, all of the antiepileptic drugs have associated adverse reactions, some of which are severe and life-threatening. Here, we review the pharmacogenomic work to date in the context of these issues and comment on key aspects of study design that are required to speed up the identification of clinically relevant genetic factors.
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Affiliation(s)
| | - Mark McCormack
- Molecular & Cellular Therapeutics, the Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Saud Alhusaini
- Molecular & Cellular Therapeutics, the Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Elijah Chaila
- The Division of Neurology, Beaumont Hospital, Dublin, Ireland
| | - Norman Delanty
- Molecular & Cellular Therapeutics, the Royal College of Surgeons in Ireland, Dublin, Ireland
- The Division of Neurology, Beaumont Hospital, Dublin, Ireland
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Abstract
Experimental and clinical evidence have demonstrated the increased synthesis of specific inflammatory mediators, and the upregulation of their cognate receptors in the chronic epileptic brain, indicating that some proinflammatory pathways are activated in seizure foci. Inhibition of experimental seizures by pharmacological interference with specific proinflammatory signaling, together with evidence of changes in intrinsic susceptibility to seizures in transgenic mice with perturbed inflammatory pathways, was instrumental to establish the concept that brain inflammation has a role in the etiopathogenesis of seizures. Increasing evidence also highlights the possible involvement of inflammatory processes arising in the injured brain in the development of epilepsy (i.e., in epileptogenesis). Since brain inflammation in epilepsy is not a mere epiphenomenon of the pathology but is likely involved in the mechanisms underlying neuronal hyperexcitability, the onset of seizures and their recurrence, it might be considered as a biomarker of disease development and severity, and, as such, could be used for diagnostic, prognostic or therapeutic purposes, provided that adequate noninvasive methodologies are developed to detect and quantify brain inflammation in humans.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Via G. La Masa 19, 20156 Milano, Italy .
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32
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Chang YT, Chen PC, Tsai IJ, Sung FC, Chin ZN, Kuo HT, Tsai CH, Chou IC. Bidirectional relation between schizophrenia and epilepsy: a population-based retrospective cohort study. Epilepsia 2011; 52:2036-42. [PMID: 21929680 DOI: 10.1111/j.1528-1167.2011.03268.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
PURPOSE Schizophrenia and epilepsy may share a mutual susceptibility. This study examined the bidirectional relation between the two disorders. METHODS We used claims data obtained from the Taiwan National Health Insurance database to conduct retrospective cohort analyses. Analysis 1 compared 5,195 patients with incident schizophrenia diagnosed in 1999-2008 with 20,776 controls without the disease randomly selected during the same period, frequency matched with sex and age. Analysis 2 comprised a similar method to compare 11,527 patients with newly diagnosed epilepsy with 46,032 randomly selected sex- and age-matched controls. At the end of 2008, analysis 1 measured the incidence and risk of developing epilepsy and analysis 2 measured the incidence and risk of developing schizophrenia. KEY FINDINGS In analysis 1, the incidence of epilepsy was higher in the schizophrenia cohort than in the nonschizophrenia cohort (6.99 vs. 1.19 per 1,000 person-years) with an adjusted hazard ratio (aHR) of 5.88 [95% confidence interval (CI) 4.71-7.36] for schizophrenia patients. In analysis 2, the incidence of schizophrenia was higher in the epilepsy cohort than in the nonepilepsy comparison cohort (3.53 vs. 0.46 per 1,000 person-years) with an aHR of 7.65 (95% CI 6.04-9.69) for epilepsy patients. The effect of schizophrenia on subsequent epilepsy was greater for women, but the association between epilepsy and elevated incidence of schizophrenia was more pronounced in men. SIGNIFICANCE We found a strong bidirectional relation between schizophrenia and epilepsy. These two conditions may share common causes. Further studies on the mechanism are required.
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Affiliation(s)
- Yu-Tzu Chang
- Division of Pediatric Neurology, Department of Pediatrics, China Medical University and Hospital, Taichung, Taiwan
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33
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Scher AI, Wu H, Tsao JW, Blom HJ, Feit P, Nevin RL, Schwab KA. MTHFR C677T Genotype As a Risk Factor for Epilepsy Including Post-Traumatic Epilepsy in a Representative Military Cohort. J Neurotrauma 2011; 28:1739-45. [DOI: 10.1089/neu.2011.1982] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Ann I. Scher
- Department of Preventive Medicine and Biometrics, Uniformed Services University, Bethesda, Maryland
| | - Holly Wu
- Department of Preventive Medicine and Biometrics, Uniformed Services University, Bethesda, Maryland
| | - Jack W. Tsao
- Department of Neurology, Uniformed Services University, Bethesda, Maryland
| | - Henk J. Blom
- Metabolic Unit, Department of Clinical Chemistry, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, the Netherlands
| | - Preethy Feit
- Department of Preventive Medicine and Biometrics, Uniformed Services University, Bethesda, Maryland
| | - Remington L. Nevin
- Bayne-Jones Army Community Hospital, Department of Preventive Medicine, Fort Polk, Louisiana
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Loiacono G, Cirillo C, Chiarelli F, Verrotti A. Focal epilepsy associated with glioneuronal tumors. ISRN NEUROLOGY 2011; 2011:867503. [PMID: 22389832 PMCID: PMC3263547 DOI: 10.5402/2011/867503] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 05/19/2011] [Indexed: 11/23/2022]
Abstract
Glioneuronal tumors are an increasingly recognized cause of partial seizures that occur primarily in children and young adults. Focal epilepsy associated with glioneuronal tumors is often resistant to pharmacological treatment. The cellular mechanisms underlying the epileptogenicity of glioneuronal tumors remain largely unknown. The involved mechanisms are certain to be multifactorial and depend on specific tumor histology, integrity of the blood-brain barrier, characteristics of the peritumoral environment, circuit abnormalities, or cellular and molecular defects. Glioneuronal tumors presenting with epilepsy were observed to have relatively benign biological behavior. The completeness of the tumor resection is of paramount importance in avoiding tumor progression and malignant transformation, which are rare in cases of epileptogenic glioneuronal tumors.
An evolving understanding of the various mechanisms of tumor-related epileptogenicity may also lead to a more defined surgical objective and effective therapeutic strategies, including antiepileptogenic treatments, to prevent epilepsy in at-risk patients.
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Affiliation(s)
- Giulia Loiacono
- Department of Paediatrics, University of Chieti, 66100 Chieti, Italy
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35
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Lv RJ, He JS, Fu YH, Zhang YQ, Shao XQ, Wu LW, Lu Q, Jin LR, Liu H. ASIC1a polymorphism is associated with temporal lobe epilepsy. Epilepsy Res 2011; 96:74-80. [PMID: 21664108 DOI: 10.1016/j.eplepsyres.2011.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 04/23/2011] [Accepted: 05/01/2011] [Indexed: 01/23/2023]
Abstract
Recent in vitro and in vivo data show that acid-sensing ion channel 1a (ASIC1a) activation enhances neuronal excitability in the hippocampus and neocortex, indicating that ASIC1a might play a role in the generation and maintenance of epileptic seizures. The aim of this study was to investigate association of the ASIC1a gene with temporal lobe epilepsy (TLE) for the first time. Six tag single-nucleotide polymorphisms (SNPs) of the ASIC1a gene were selected and genotyped using polymerase chain reaction-restriction fragment length polymorphism in 560 TLE patients and 401 healthy controls. There was a significant allelic and genotypic association between rs844347:A>C and TLE compared with controls. The rs844347-A allele frequency was 88.1% in the patients and 83.0% in control subjects (OR=1.516, 95% CI 1.142-2.013, p=0.004). Furthermore, the haplotype analysis revealed a significant association with TLE. The results of this study demonstrate for the first time an association between an ASC1a variant allele and TLE in a Han Chinese population.
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Affiliation(s)
- Rui-Juan Lv
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China
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Haerian BS, Lim KS, Tan HJ, Wong CP, Wong SW, Tan CT, Raymond AA, Mohamed Z. Lack of association between synapsin II (SYN2) gene polymorphism and susceptibility epilepsy: a case-control study and meta-analysis. Synapse 2011; 65:1073-9. [PMID: 21465568 DOI: 10.1002/syn.20939] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Accepted: 03/24/2011] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The SYN2 rs3773364 A>G polymorphism has been proposed to be involved in susceptibility to epilepsy, but research results have been inconclusive. The aim of this study was to investigate the association between the SYN2 rs3773364 A>G polymorphism and susceptibility against epilepsy in a case-control study and a meta-analysis. METHODS The SYN2 rs3773364 A>G polymorphism was successfully genotyped in 1182 samples (618 epilepsy patients) of Chinese, Indian, and Malay ethnicities. Meta-analysis of the related studies, including this case-control study, was performed under alternative genetic models. RESULTS Data from the case-control study indicated no allelic and genotypic association of this locus with susceptibility to epilepsy in the tri-ethnic Malaysian population. Similar finding was obtained by stratified analysis by epilepsy syndrome for idiopathic epilepsy. These results were verified by meta-analysis of the related pooled data. CONCLUSIONS Our study indicated that SYN2 rs3773364 A>G polymorphism is not a risk factor for susceptibility to epilepsy.
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Affiliation(s)
- Batoul Sadat Haerian
- Pharmacogenomics Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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A polymorphism in CALHM1 is associated with temporal lobe epilepsy. Epilepsy Behav 2011; 20:681-5. [PMID: 21439911 DOI: 10.1016/j.yebeh.2011.02.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 01/13/2011] [Accepted: 02/05/2011] [Indexed: 11/23/2022]
Abstract
A recent study suggests that the P86L polymorphism (rs2986017) in the calcium homeostasis modulator 1 (CALHM1) gene interferes with calcium homeostasis and increases amyloid β (Aβ) levels. Moreover, in vitro and in vivo data show that both calcium homeostasis and high levels of Aβ play an important role in the induction and maintenance of epileptic seizures in hippocampus, indicating CALHM1 might play a potential role in pathophysiological pathways involved in temporal lobe epilepsy (TLE). The aim of this study was to investigate the genetic contribution of CALHM1 to TLE. Five single-nucleotide polymorphisms (SNPs) of CALHM1 were selected and genotyped using polymerase chain reaction restriction fragment length polymorphism in 560 patients with TLE and 401 healthy controls. We found a positive association between rs11191692 and TLE, but a negative result between rs2986017 and TLE. The rs11191692-A allele frequency was found in 32.4% of the patients and in 26.2% of control subjects (OR=1.35, 95% CI=1.10-1.65, uncorrected P=0.003, corrected P=0.015). Furthermore, the positive association between rs11191692 and TLE independent of apolipoprotein E ε4 was supported by five SNPs haplotype analysis. The results of this study provide the first evidence that the SNP rs11191692 in CALHM1 confers highly increased susceptibility to TLE.
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Haerian BS, Lim KS, Tan CT, Raymond AA, Mohamed Z. Association of ABCB1 gene polymorphisms and their haplotypes with response to antiepileptic drugs: a systematic review and meta-analysis. Pharmacogenomics 2011; 12:713-25. [PMID: 21391884 DOI: 10.2217/pgs.10.212] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIMS Several studies demonstrated a link between ABCB1 gene variants and the response to treatment in epilepsy, but the results have been inconclusive. Here, we performed the first haplotype meta-analysis to examine the association of haplotypes of ABCB1 common variants with the response to treatment in epilepsy. MATERIALS & METHODS We meta-analyzed the studies that evaluated the role of ABCB1 C1236T, G2677T/A and C3435T polymorphisms and their haplotypes in the response to treatment. RESULTS Meta-analysis of 23 studies (7067 patients) showed no significant association of ABCB1 alleles, genotypes and haplotypes with the response to treatment in the overall population or in each ethnicity subgroup. CONCLUSION Our data suggest that the haplotypes of these loci may not be involved in the response to treatment.
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Affiliation(s)
- Batoul Sadat Haerian
- Pharmacogenomics Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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Dai AI, Bay A, Gorucu S, Sivasli E, Bosnak M. KCNJ10 potassium ion channel single nucleotide polymorphism in pediatric patients with idiopathic generalized epilepsy. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.npbr.2011.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Labate A, Gambardella A, Andermann E, Aguglia U, Cendes F, Berkovic SF, Andermann F. Benign mesial temporal lobe epilepsy. Nat Rev Neurol 2011; 7:237-40. [PMID: 21263461 DOI: 10.1038/nrneurol.2010.212] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Benign mesial temporal lobe epilepsy (bMTLE), which is defined as at least 24 months of seizure freedom with or without antiepileptic medication, has probably been under-recognized because of a literature bias toward refractory epilepsy cases. Seizure onset in bMTLE tends to be in adolescence or adulthood, and patients frequently have a family history of febrile seizures and epilepsy. Long-term seizure freedom is observed with or without antiepileptic medication. On brain MRI, nearly 40% of patients with long-standing bMTLE show evidence of hippocampal sclerosis, a feature usually associated with refractory temporal lobe epilepsy. Prospective studies are needed to determine the features that allow prediction of a benign course, and to clarify the significance of hippocampal MRI changes.
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Affiliation(s)
- Angelo Labate
- Institute of Neurology, University Magna Graecia, Viale Europa, 88100 Catanzaro, Italy
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Valachis A, Mauri D, Neophytou C, Polyzos NP, Tsali L, Garras A, Papanikolau EG. Translational medicine and reliability of single-nucleotide polymorphism studies: can we believe in SNP reports or not? Int J Med Sci 2011; 8:492-500. [PMID: 21897762 PMCID: PMC3167098 DOI: 10.7150/ijms.8.492] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Accepted: 08/09/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The number of genetic association studies is increasing exponentially. Nonetheless, genetic association reports are prone to potential biases which may influence the reported outcome. AIM We hypothesized that positive outcome for a determined polymorphism might be over-reported across genetic association studies analysing a small number of polymorphisms, when compared to studies analysing the same polymorphism together with a high number of other polymorphisms. METHODS We systematically reviewed published reports on the association of glutathione s-transferase (GST) single-nucleotide polymorphisms (SNPs) and cancer outcome. RESULT We identified 79 eligible trials. Most of the studies examined the GSTM1, theGSTP1 Ile105Val mutation, and GSTT1polymorphisms (n = 54, 57 and 46, respectively). Studies analysing one to three polymorphisms (n = 39) were significantly more likely to present positive outcomes, compared to studies examining more than 3 polymorphisms (n=40) p = 0.004; this was particularly evident for studies analysing the GSTM1polymorphism (p =0.001). We found no significant associations between journal impact factor, number of citations, and probability of publishing positive studies or studies with 1-3 polymorphisms examined. CONCLUSIONS We propose a new subtype of publication bias in genetic association studies. Positive results for genetic association studies analysing a small number of polymorphisms (n = 1-3) should be evaluated extremely cautiously, because a very large number of such studies are inconclusive and statistically under-powered. Indeed, publication of misleading reports may affect harmfully medical decision-making and use of resources, both in clinical and pharmacological development setting.
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Muto T. A proposal of a novel experimental procedure to genetically identify disease gene loci in humans. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2011; 87:91-103. [PMID: 21422742 PMCID: PMC3066544 DOI: 10.2183/pjab.87.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Accepted: 01/28/2011] [Indexed: 05/30/2023]
Abstract
Forward genetics in humans is beneficial in terms of diagnosis and treatment of genetic diseases, and discovery of gene functions. However, experimental mating is not possible among humans. In order to overcome this problem, I propose a novel experimental procedure to genetically identify human disease gene loci. To accomplish this, somatic cells from patients or their parents are reprogrammed to the pluripotent state, oogenesis is induced, the oocytes are parthenogenetically activated in the presence of cytochalasin, and embryonic stem cells are established from the parthenogenetic blastocysts. This protocol produces a set of diploid pluripotent stem cell clones having maternal and paternal chromosomes in different manners to each other. The genetic loci for the disease genes are determined through the conventional processes of positional cloning. Thus, taking advantage of the strategy proposed here, if the abnormality is reproducible using patient-derived pluripotent stem cells, a single carrier of the genetic mutations would be adequate to identify the disease gene loci.
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Affiliation(s)
- Taro Muto
- Department of Molecular Biology, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan.
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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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Jamali S, Salzmann A, Perroud N, Ponsole-Lenfant M, Cillario J, Roll P, Roeckel-Trevisiol N, Crespel A, Balzar J, Schlachter K, Gruber-Sedlmayr U, Pataraia E, Baumgartner C, Zimprich A, Zimprich F, Malafosse A, Szepetowski P. Functional variant in complement C3 gene promoter and genetic susceptibility to temporal lobe epilepsy and febrile seizures. PLoS One 2010; 5. [PMID: 20862287 PMCID: PMC2940893 DOI: 10.1371/journal.pone.0012740] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 08/18/2010] [Indexed: 01/11/2023] Open
Abstract
Background Human mesial temporal lobe epilepsies (MTLE) represent the most frequent form of partial epilepsies and are frequently preceded by febrile seizures (FS) in infancy and early childhood. Genetic associations of several complement genes including its central component C3 with disorders of the central nervous system, and the existence of C3 dysregulation in the epilepsies and in the MTLE particularly, make it the C3 gene a good candidate for human MTLE. Methodology/Principal Findings A case-control association study of the C3 gene was performed in a first series of 122 patients with MTLE and 196 controls. Four haplotypes (HAP1 to 4) comprising GF100472, a newly discovered dinucleotide repeat polymorphism [(CA)8 to (CA)15] in the C3 promoter region showed significant association after Bonferroni correction, in the subgroup of MTLE patients having a personal history of FS (MTLE-FS+). Replication analysis in independent patients and controls confirmed that the rare HAP4 haplotype comprising the minimal length allele of GF100472 [(CA)8], protected against MTLE-FS+. A fifth haplotype (HAP5) with medium-size (CA)11 allele of GF100472 displayed four times higher frequency in controls than in the first cohort of MTLE-FS+ and showed a protective effect against FS through a high statistical significance in an independent population of 97 pure FS. Consistently, (CA)11 allele by its own protected against pure FS in a second group of 148 FS patients. Reporter gene assays showed that GF100472 significantly influenced C3 promoter activity (the higher the number of repeats, the lower the transcriptional activity). Taken together, the consistent genetic data and the functional analysis presented here indicate that a newly-identified and functional polymorphism in the promoter of the complement C3 gene might participate in the genetic susceptibility to human MTLE with a history of FS, and to pure FS. Conclusions/Significance The present study provides important data suggesting for the first time the involvement of the complement system in the genetic susceptibility to epileptic seizures and to epilepsy.
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Affiliation(s)
- Sarah Jamali
- INSERM UMR 910, University of Méditerranée, Marseille, France
| | - Annick Salzmann
- Department of Medical Genetics and Development, University Hospital of Geneva, Geneva, Switzerland
| | - Nader Perroud
- Department of Psychiatry, University Hospital of Geneva, Geneva, Switzerland
| | - Magali Ponsole-Lenfant
- Mediterranean Institute of Neurobiology (INMED), INSERM UMR901, University of Méditerranée, Marseille, France
| | - Jennifer Cillario
- Mediterranean Institute of Neurobiology (INMED), INSERM UMR901, University of Méditerranée, Marseille, France
| | - Patrice Roll
- INSERM UMR 910, University of Méditerranée, Marseille, France
| | | | - Ariel Crespel
- Epilepsy Unit, University Hospital of Montpellier, Montpellier, France
| | - Jorg Balzar
- Department of Clinical Neurology, Medical University of Vienna, Vienna, Austria
| | | | | | - Ekaterina Pataraia
- Department of Clinical Neurology, Medical University of Vienna, Vienna, Austria
| | - Christoph Baumgartner
- 2nd Neurological Department, General Hospital Hietzing with Neurological Center Rosenhuegel, Vienna, Austria
| | - Alexander Zimprich
- Department of Clinical Neurology, Medical University of Vienna, Vienna, Austria
| | - Fritz Zimprich
- Department of Clinical Neurology, Medical University of Vienna, Vienna, Austria
| | - Alain Malafosse
- Department of Medical Genetics and Development, University Hospital of Geneva, Geneva, Switzerland
- Department of Psychiatry, University Hospital of Geneva, Geneva, Switzerland
- * E-mail: (PS); (AM)
| | - Pierre Szepetowski
- INSERM UMR 910, University of Méditerranée, Marseille, France
- Mediterranean Institute of Neurobiology (INMED), INSERM UMR901, University of Méditerranée, Marseille, France
- * E-mail: (PS); (AM)
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Heuser K, Hoddevik EH, Taubøll E, Gjerstad L, Indahl U, Kaczmarek L, Berg PR, Lien S, Nagelhus EA, Ottersen OP. Temporal Lobe Epilepsy and Matrix Metalloproteinase 9: A tempting relation but negative genetic association. Seizure 2010; 19:335-8. [DOI: 10.1016/j.seizure.2010.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 05/03/2010] [Accepted: 05/07/2010] [Indexed: 01/26/2023] Open
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Abstract
The mechanisms that transform a normal brain to an epileptic one are not fully understood. Interleukin-1 beta (IL-1beta) contributes to neuronal degeneration observed in several neurological disorders and recently has been implicated in neuronal injury that may accompany the process of epileptogenesis. This review presents the hypothesis that IL-1beta may contribute to the development of epilepsy via several mechanisms, including classical effects on neuronal survival and transcription pathways; novel rapid effects on receptor-gated ion channels; and long-lasting effects on expression of selective gene families. Thus, evidence that IL-1beta actions in epilepsy can be independent from the neurotoxic effects of this cytokine is presented.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Milano, Italy.
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Kauffman MA, Consalvo D, Moron DG, Lereis VP, Kochen S. ApoE epsilon4 genotype and the age at onset of temporal lobe epilepsy: a case-control study and meta-analysis. Epilepsy Res 2010; 90:234-9. [PMID: 20554432 DOI: 10.1016/j.eplepsyres.2010.05.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Revised: 05/03/2010] [Accepted: 05/16/2010] [Indexed: 11/26/2022]
Abstract
In order to investigate the role of ApoE epsilon4 as a modifier of the age at onset of temporal lobe epilepsy (TLE), we performed a molecular epidemiology study in 78 patients with mesial temporal lobe epilepsy and hippocampal sclerosis. Genotyping was done by a PCR-RFLP assay. In order to better estimate the role of this variant as a modifier of the age at onset, we also performed a systematic review of the literature. We included our results into a meta-analysis along with data available from seven published studies with 728 patients that looked into the role of ApoE epsilon4 in TLE. We found that ApoE epsilon4 carriers in our population had a non-significant earlier age of epilepsy onset than non-carriers. The meta-analysis confirmed this finding, showing that ApoE epsilon4 carriers had epilepsy onset almost 4 years earlier than non-carriers (mean difference 5.15 years; CI 95% 2.08-6.22; p=0.001). In conclusion, the ApoE epsilon4 isoform is a genetic factor that might influence the age at onset of TLE.
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Affiliation(s)
- Marcelo Andrés Kauffman
- Consultorio de Neurogenética, Centro de Epilepsia, Centro Universitario de Neurología, Hospital JM Ramos Mejia, IBCN Eduardo de Robertis, CONICET, Buenos Aires, Argentina.
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Kasperaviciūte D, Catarino CB, Heinzen EL, Depondt C, Cavalleri GL, Caboclo LO, Tate SK, Jamnadas-Khoda J, Chinthapalli K, Clayton LMS, Shianna KV, Radtke RA, Mikati MA, Gallentine WB, Husain AM, Alhusaini S, Leppert D, Middleton LT, Gibson RA, Johnson MR, Matthews PM, Hosford D, Heuser K, Amos L, Ortega M, Zumsteg D, Wieser HG, Steinhoff BJ, Krämer G, Hansen J, Dorn T, Kantanen AM, Gjerstad L, Peuralinna T, Hernandez DG, Eriksson KJ, Kälviäinen RK, Doherty CP, Wood NW, Pandolfo M, Duncan JS, Sander JW, Delanty N, Goldstein DB, Sisodiya SM. Common genetic variation and susceptibility to partial epilepsies: a genome-wide association study. ACTA ACUST UNITED AC 2010; 133:2136-47. [PMID: 20522523 PMCID: PMC2892941 DOI: 10.1093/brain/awq130] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Partial epilepsies have a substantial heritability. However, the actual genetic causes are largely unknown. In contrast to many other common diseases for which genetic association-studies have successfully revealed common variants associated with disease risk, the role of common variation in partial epilepsies has not yet been explored in a well-powered study. We undertook a genome-wide association-study to identify common variants which influence risk for epilepsy shared amongst partial epilepsy syndromes, in 3445 patients and 6935 controls of European ancestry. We did not identify any genome-wide significant association. A few single nucleotide polymorphisms may warrant further investigation. We exclude common genetic variants with effect sizes above a modest 1.3 odds ratio for a single variant as contributors to genetic susceptibility shared across the partial epilepsies. We show that, at best, common genetic variation can only have a modest role in predisposition to the partial epilepsies when considered across syndromes in Europeans. The genetic architecture of the partial epilepsies is likely to be very complex, reflecting genotypic and phenotypic heterogeneity. Larger meta-analyses are required to identify variants of smaller effect sizes (odds ratio <1.3) or syndrome-specific variants. Further, our results suggest research efforts should also be directed towards identifying the multiple rare variants likely to account for at least part of the heritability of the partial epilepsies. Data emerging from genome-wide association-studies will be valuable during the next serious challenge of interpreting all the genetic variation emerging from whole-genome sequencing studies.
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Affiliation(s)
- Dalia Kasperaviciūte
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
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Haerian BS, Roslan H, Raymond AA, Tan CT, Lim KS, Zulkifli SZ, Mohamed EHM, Tan HJ, Mohamed Z. ABCB1 C3435T polymorphism and the risk of resistance to antiepileptic drugs in epilepsy: a systematic review and meta-analysis. Seizure 2010; 19:339-46. [PMID: 20605481 DOI: 10.1016/j.seizure.2010.05.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Revised: 04/30/2010] [Accepted: 05/07/2010] [Indexed: 01/16/2023] Open
Abstract
OBJECTIVE The C3435T, a major allelic variant of the ABCB1 gene, is proposed to play a crucial role in drug-resistance in epilepsy. The C/C genotype carriers reportedly are at higher risk of pharmacoresistance to AEDs, but only in some studies. The hypothesis of the C-variant associated risk and resistance to antiepileptic drugs (AEDs) has been hampered by conflicting results from inadequate power in case-control studies. To assess the role of C3435T polymorphism in drug-resistance in epilepsy, a systematic review and meta-analysis was conducted. METHODS Databases were obtained from the Cochrane Library, MEDLINE, EMBASE, major American and European conference abstracts, and www.google.my for genetic association studies up to February 2010. All the case-control association studies evaluating the role of ABCB1 C3435T in pharmacoresistance to AEDs were identified. The new definition of treatment outcome from International League Against Epilepsy (ILAE) was used for including studies for sub-analysis. To measure the strength of genetic association for the gene variant, the odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using models of both fixed- and random-effects for comparisons of the alleles and genotypes with co-dominant (C/C vs. T/T, C/T vs. T/T), dominant (C/C+C/T vs. T/T), and recessive (C/C vs. C/T+T/T) models in overall and in ethnicity subgroups. The 19 studies were selected for the next sub-analysis based on the new definition of drug-responsiveness and drug-resistance from ILAE. The same analysis was also performed for treatment outcome and ethnicity subgroups. RESULTS A total of 22 association studies including 3231 (47.8%) drug-resistant patients and 3524 (52.2%) drug-responsive patients or healthy controls (genotyped for C3435T) were pooled in this meta-analysis. The allelic association of ABCB1 C3435T with risk of drug-resistance was not significant under fixed-effects model, 1.06 (95% CI 0.98-1.14, p=0.12) and random-effects model, 1.10 (0.93-1.30, p=0.28) in overall and in the subgroup analysis by ethnicity. Similar results were also obtained for all genetic models in the stratified analyses by new definition of drug-resistance by ILAE and ethnicity subgroups. There was no publication bias. CONCLUSION We failed to show an association between the ABCB1 C3435T polymorphism and the risk of drug-resistance suggesting a revision in contribution of this polymorphism in the multi-drug transporters hypothesis of pharmacoresistance to AEDs in epilepsy.
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Affiliation(s)
- B S Haerian
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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Ottman R, Hirose S, Jain S, Lerche H, Lopes-Cendes I, Noebels JL, Serratosa J, Zara F, Scheffer IE. Genetic testing in the epilepsies--report of the ILAE Genetics Commission. Epilepsia 2010; 51:655-70. [PMID: 20100225 DOI: 10.1111/j.1528-1167.2009.02429.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this report, the International League Against Epilepsy (ILAE) Genetics Commission discusses essential issues to be considered with regard to clinical genetic testing in the epilepsies. Genetic research on the epilepsies has led to the identification of more than 20 genes with a major effect on susceptibility to idiopathic epilepsies. The most important potential clinical application of these discoveries is genetic testing: the use of genetic information, either to clarify the diagnosis in people already known or suspected to have epilepsy (diagnostic testing), or to predict onset of epilepsy in people at risk because of a family history (predictive testing). Although genetic testing has many potential benefits, it also has potential harms, and assessment of these potential benefits and harms in particular situations is complex. Moreover, many treating clinicians are unfamiliar with the types of tests available, how to access them, how to decide whether they should be offered, and what measures should be used to maximize benefit and minimize harm to their patients. Because the field is moving rapidly, with new information emerging practically every day, we present a framework for considering the clinical utility of genetic testing that can be applied to many different syndromes and clinical contexts. Given the current state of knowledge, genetic testing has high clinical utility in few clinical contexts, but in some of these it carries implications for daily clinical practice.
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Affiliation(s)
- Ruth Ottman
- G. H. Sergievsky Center and Department of Epidemiology, Columbia University, New York, NY, USA.
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