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Asadi-Pooya AA, Malekpour M, Taherifard E, Mallahzadeh A, Farjoud Kouhanjani M. Coexistence of temporal lobe epilepsy and idiopathic generalized epilepsy. Epilepsy Behav 2024; 151:109602. [PMID: 38160579 DOI: 10.1016/j.yebeh.2023.109602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 12/07/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
OBJECTIVE We investigated the frequency of coexistence of temporal lobe epilepsy (TLE) and idiopathic generalized epilepsy (IGE) in a retrospective database study. We also explored the underlying pathomechanisms of the coexistence of TLE and IGE based on the available information, using bioinformatics tools. METHODS The first phase of the investigation was a retrospective study. All patients with an electro-clinical diagnosis of epilepsy were studied at the outpatient epilepsy clinic at Shiraz University of Medical Sciences, Shiraz, Iran, from 2008 until 2023. In the second phase, we searched the following databases for genetic variations (epilepsy-associated genetic polymorphisms) that are associated with TLE or syndromes of IGE: DisGeNET, genome-wide association study (GWAS) Catalog, epilepsy genetic association database (epiGAD), and UniProt. We also did a separate literature search using PubMed. RESULTS In total, 3760 patients with epilepsy were registered at our clinic; four patients with definitely mixed TLE and IGE were identified; 0.1% of all epilepsies. We could identify that rs1883415 of ALDH5A1, rs137852779 of EFHC1, rs211037 of GABRG2, rs1130183 of KCNJ10, and rs1045642 of ABCB1 genes are shared between TLE and syndromes of IGE. CONCLUSION While coexistence of TLE and IGE is a rare phenomenon, this could be explained by shared genetic variations.
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Affiliation(s)
- Ali A Asadi-Pooya
- Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran; Jefferson Comprehensive Epilepsy Center, Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.
| | - Mahdi Malekpour
- Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ehsan Taherifard
- Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Arashk Mallahzadeh
- Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Saleem T, Maqbool H, Sheikh N, Tayyeb A, Mukhtar M, Ashfaq A. GABRG2 C588T Polymorphism Is Associated with Idiopathic Generalized Epilepsy but Not with Antiepileptic Drug Resistance in Pakistani Cohort. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3460792. [PMID: 36425336 PMCID: PMC9681559 DOI: 10.1155/2022/3460792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 10/19/2022] [Accepted: 10/29/2022] [Indexed: 08/30/2023]
Abstract
Idiopathic generalized epilepsy (IGE) is the most prevalent type of epilepsy with genetic origin. Mutations in ion channel genes have been identified as a common cause of IGE. Several studies have reported various epilepsy risk variants of GABRG2 (gamma-aminobutyric acid type A receptor subunit gamma2 subunit) gene in different ethnic groups, but the results are inconsistent. The purpose of this case-control research is to determine if GABRG2 polymorphisms contribute to IGE susceptibility and antiepileptic drug resistance in Pakistani population. For this purpose, we genotyped exon2, exon5 (C540T and C588T), exon7 (T813C), exon8 (K289M), and exon9 of GABRG2 gene by restriction fragment length polymorphism and Sanger's sequencing in 87 drug-responsive idiopathic generalized epilepsy patients, 55 drug-resistant epilepsy patients, and 83 healthy controls. Restriction fragment length polymorphism (RFLP) and sequencing results indicated only C588T polymorphism in the studied subjects. The comparison of genotypic and allelic frequencies showed significant differences between IGE patients and control groups (P = 0.008 and odds ratio = 4.2) and nonsignificant association of C588T polymorphism in antiseizure medication-resistant patients (P = 0.9). Our findings showed that C588T polymorphism of GABRG2 is a risk variant for IGE in Pakistani population. Further studies are required to validate the results.
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Affiliation(s)
- Tayyaba Saleem
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Hafsa Maqbool
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Nadeem Sheikh
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Asima Tayyeb
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Maryam Mukhtar
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
| | - Aqsa Ashfaq
- Cell and Molecular Biology Laboratory, Institute of Zoology, University of the Punjab, Lahore, Pakistan
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Ullah S, Ali N, Ahmad S, Sha SWA, Ali S, Almarshad F. The likelihood approach for potential role of "GABRG2 (C588T, C315T) gene polymorphisms" on the poor response to carbamazepine therapy in Pakhtun population of Pakistan. Medicine (Baltimore) 2022; 101:e30948. [PMID: 36221407 PMCID: PMC9542555 DOI: 10.1097/md.0000000000030948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Gamma-aminobutyric acid A receptor, gamma 2 gene (GABRG2) encode the GABAA receptor which is responsible for fast neuronal inhibition. Polymorphisms in GABGR2 gene affect the clinical response of anti-epileptic drugs (AEDs). Therefore, we carried out an updated study to find the association GABRG2 gene polymorphisms with carbamazepine (CBZ) non-responsive therapy in the Pakhtun population. METHODS A clinical prospective cohort study was conducted in 79 CBZ treated patients upon consent after the approval of Khyber Medical University Advanced Study and Research Board. Blood sample were taken at optimal dose of CBZ at base line, third and sixth months of the treatment. Blood level of CBZ was measure through reverse phase high performance liquid chromatography (HPLC). Restriction fragment length polymorphisms techniques were used to genotype GABRG2 gene in these patients. CBZ responses were evaluated on three and six months of study by measuring the decrease in frequency of seizure per week. RESULTS The average maximum dose of CBZ was 455 ± 133 mg/day at baseline, 479 ± 142 mg/day at third month and 495 ± 133 mg/day at sixth month of the treatment. CBZ level was found within therapeutic range (4-12 mg/L) without any significant (P > .5) variations among the CC, CT and TT genotypes of GABRG2 (C588T and C315T) gene. But the poor clinical response during CBZ treatment was linked (P < .05) with CT and TT genotypes of GABRG2 (C588T and C315T) gene in Pakhtun Population. CONCLUSION A poor response to CBZ was found in variant genotypes (CT and TT) of GABRG2 (C588T and C315T) gene in Pakhtun Population.
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Affiliation(s)
- Shakir Ullah
- Department of Pharmacology Institute of Basic Medical Science, Khyber Medical University, Peshawar, Khyber Pakhtunkhwa, Pakistan
- * Correspondence: Shakir Ullah, Institute of Basic Medical Sciences/Institute of Pharmaceutical Sciences, Khyber Medical University, Peshawar, Khyber Pakhtunkhwa, Pakistan (e-mail: )
| | - Niaz Ali
- Department of Pharmacology Institute of Basic Medical Science, Khyber Medical University, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Sajjad Ahmad
- Department of Pharmacology Institute of Basic Medical Science, Khyber Medical University, Peshawar, Khyber Pakhtunkhwa, Pakistan
| | - Syed Wadood Ali Sha
- Department of Pharmacy (Pharmacology), University of Malakand, Chakdara, Pakistan
| | - Saad Ali
- Department of Neurology, Govt. Lady Reading Hospital Peshawar, Khyber Pakhtunkhwa, Pakistan
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Amjad M, Tabassum A, Sher K, Kumar S, Zehra S, Fatima S. Impact of GABAA receptor gene variants (rs2279020 and rs211037) on the risk of predisposition to epilepsy: a case–control study. Neurol Sci 2022; 43:4431-4438. [DOI: 10.1007/s10072-022-05947-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/08/2022] [Indexed: 10/19/2022]
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GABRA1 and GABRA6 gene mutations in idiopathic generalized epilepsy patients. Seizure 2021; 93:88-94. [PMID: 34740144 DOI: 10.1016/j.seizure.2021.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 10/14/2021] [Accepted: 10/16/2021] [Indexed: 12/25/2022] Open
Abstract
The GABA receptor is an important epilepsy-associated candidate gene, and has always been a focus in etiology and in the treatment of epilepsy. This study explores the genetic association between GABA receptor gene polymorphisms and epilepsy in a cohort of the Pakistani population. A case-control study was conducted on 150 patients with idiopathic generalized epilepsy (IGE) and 150 controls. Blood samples were collected, and genomic DNA was extracted and amplified using polymerase chain reaction (PCR). The amplified products were subsequently genotyped by Sanger sequencing and the results were analyzed using the chi-square test. Among the five mutational sites observed, two GABRA1 (rs2279020 and novel c.1016_1017insT) and two GABRA6 (rs3219151 and novel c.1344C>G) were found to be significantly associated with IGE. Amino acid alignment showed that a novel insertion mutation, c.1016_1017insT, in GABRA1 disrupted the reading frame and was possibly damaging, whereas c.1344C>G in GABRA6 was responsible for a synonymous mutation. Therefore, both the GABA receptor genes may play critical roles in the development of epilepsy in Pakistani patients.
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Yang X, Ding H, Wei H, Liu J, Liao P, Zhang Y, Wang X, Chi X. Association between GABRG2 rs211037 polymorphism and idiopathic generalized epilepsies: a meta-analysis. ACTA EPILEPTOLOGICA 2021. [DOI: 10.1186/s42494-021-00043-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Abstract
Background
We performed this meta-analysis to investigate the association between GABRG2 rs211037polymorphism and the risk for idiopathic generalized epilepsies (IGEs).
Methods
Medline, Embase, Cochrane Library and Chinese National Knowledge Infrastructure (CNKI) databases were searched for eligible studies (until May 5, 2020) on the association between GABRG2 rs211037 polymorphism and IGE. The odds ratios were calculated using a fixed or random model in STATA 15.0 software. Subgroup analyses for ethnicity, age, source of controls, type of seizure syndrome and therapeutic responses were conducted.
Results
We found no significant associations between GABRG2 rs211037 polymorphism and the susceptibility to IGEs. In addition, no significant association was detected between GABRG2 rs211037 polymorphism and drug resistance in IGE patients. The results did not change after stratification by Asian population, healthy controls, children, juvenile myoclonic epilepsy, and childhood absence epilepsy.
Conclusion
The current studies indicated that the GABRG2 rs211037 polymorphism was not related to susceptibility or drug resistance of IGE. Further well-designed studies are needed to verify the results.
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Liao M, Kundap U, Rosch RE, Burrows DRW, Meyer MP, Ouled Amar Bencheikh B, Cossette P, Samarut É. Targeted knockout of GABA-A receptor gamma 2 subunit provokes transient light-induced reflex seizures in zebrafish larvae. Dis Model Mech 2019; 12:dmm.040782. [PMID: 31582559 PMCID: PMC6899022 DOI: 10.1242/dmm.040782] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/24/2019] [Indexed: 12/29/2022] Open
Abstract
Epilepsy is a common primary neurological disorder characterized by the chronic tendency of a patient to experience epileptic seizures, which are abnormal body movements or cognitive states that result from excessive, hypersynchronous brain activity. Epilepsy has been found to have numerous etiologies and, although about two-thirds of epilepsies were classically considered idiopathic, the majority of those are now believed to be of genetic origin. Mutations in genes involved in gamma-aminobutyric acid (GABA)-mediated inhibitory neurotransmission have been associated with a broad range of epilepsy syndromes. Mutations in the GABA-A receptor gamma 2 subunit gene (GABRG2), for example, have been associated with absence epilepsy and febrile seizures in humans. Several rodent models of GABRG2 loss of function depict clinical features of the disease; however, alternative genetic models more amenable for the study of ictogenesis and for high-throughput screening purposes are still needed. In this context, we generated a gabrg2 knockout (KO) zebrafish model (which we called R23X) that displayed light/dark-induced reflex seizures. Through high-resolution in vivo calcium imaging of the brain, we showed that this phenotype is associated with widespread increases in neuronal activity that can be effectively alleviated by the anti-epileptic drug valproic acid. Moreover, these seizures only occur at the larval stages but disappear after 1 week of age. Interestingly, our whole-transcriptome analysis showed that gabrg2 KO does not alter the expression of genes in the larval brain. As a result, the gabrg2−/− zebrafish is a novel in vivo genetic model of early epilepsies that opens new doors to investigate ictogenesis and for further drug-screening assays. Summary: The authors present a novel in vivo genetic model of idiopathic epilepsy in zebrafish (gabrg2−/−) to aid the study of ictogenesis and provide a convenient genetic tool for drug screening.
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Affiliation(s)
- Meijiang Liao
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Uday Kundap
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Richard E Rosch
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Paediatric Neurology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| | - Dominic R W Burrows
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Martin P Meyer
- Department for Developmental Neurobiology, MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.,Department for Developmental Neurobiology, Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Bouchra Ouled Amar Bencheikh
- Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada.,Neuroscience Department, Centre de Recherche, Centre Hospitalier de l'Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Patrick Cossette
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada
| | - Éric Samarut
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada .,Modelis Inc., Montréal, QC H2X 0A9, Canada
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Hixson KM, Cogswell M, Brooks-Kayal AR, Russek SJ. Evidence for a non-canonical JAK/STAT signaling pathway in the synthesis of the brain's major ion channels and neurotransmitter receptors. BMC Genomics 2019; 20:677. [PMID: 31455240 PMCID: PMC6712773 DOI: 10.1186/s12864-019-6033-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 08/15/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Brain-derived neurotrophic factor (BDNF) is a major signaling molecule that the brain uses to control a vast network of intracellular cascades fundamental to properties of learning and memory, and cognition. While much is known about BDNF signaling in the healthy nervous system where it controls the mitogen activated protein kinase (MAPK) and cyclic-AMP pathways, less is known about its role in multiple brain disorders where it contributes to the dysregulated neuroplasticity seen in epilepsy and traumatic brain injury (TBI). We previously found that neurons respond to prolonged BDNF exposure (both in vivo (in models of epilepsy and TBI) and in vitro (in BDNF treated primary neuronal cultures)) by activating the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signaling pathway. This pathway is best known for its association with inflammatory cytokines in non-neuronal cells. RESULTS Here, using deep RNA-sequencing of neurons exposed to BDNF in the presence and absence of well characterized JAK/STAT inhibitors, and without non-neuronal cells, we determine the BDNF transcriptome that is specifically regulated by agents that inhibit JAK/STAT signaling. Surprisingly, the BDNF-induced JAK/STAT transcriptome contains ion channels and neurotransmitter receptors coming from all the major classes expressed in the brain, along with key modulators of synaptic plasticity, neurogenesis, and axonal remodeling. Analysis of this dataset has revealed a unique non-canonical mechanism of JAK/STATs in neurons as differential gene expression mediated by STAT3 is not solely dependent upon phosphorylation at residue 705 and may involve a BDNF-induced interaction of STAT3 with Heterochromatin Protein 1 alpha (HP1α). CONCLUSIONS These findings suggest that the neuronal BDNF-induced JAK/STAT pathway involves more than STAT3 phosphorylation at 705, providing the first evidence for a non-canonical mechanism that may involve HP1α. Our analysis reveals that JAK/STAT signaling regulates many of the genes associated with epilepsy syndromes where BDNF levels are markedly elevated. Uncovering the mechanism of this novel form of BDNF signaling in the brain may provide a new direction for epilepsy therapeutics and open a window into the complex mechanisms of STAT3 transcriptional regulation in neurological disease.
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Affiliation(s)
- Kathryn M. Hixson
- Laboratory of Translational Epilepsy, Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine (BUSM), Boston, USA
- Graduate Program for Neuroscience (GPN), Boston University (BU), Boston, USA
| | - Meaghan Cogswell
- Laboratory of Translational Epilepsy, Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine (BUSM), Boston, USA
| | - Amy R. Brooks-Kayal
- Department of Pediatric Neurology, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Shelley J. Russek
- Laboratory of Translational Epilepsy, Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine (BUSM), Boston, USA
- Graduate Program for Neuroscience (GPN), Boston University (BU), Boston, USA
- Department of Biology, Boston University (BU), Boston, USA
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The genetic variant "C588T" of GABARG2 is linked to childhood idiopathic generalized epilepsy and resistance to antiepileptic drugs. Seizure 2018; 60:39-43. [PMID: 29894917 DOI: 10.1016/j.seizure.2018.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 06/03/2018] [Accepted: 06/05/2018] [Indexed: 11/21/2022] Open
Abstract
PURPOSE Previous studies have suggested that GABARG2 (Gamma-Aminobutyric acid type A Receptor Gamma 2 subunit) could be a gene of interest in genetic epilepsy; through possible associations with increased epilepsy susceptibility or resistance to antiepileptic drugs. The present study was designed to explore whether the GABARG2 C588 T (rs211037) genetic variant predicts susceptibility to epilepsy and pharmacoresistance among Egyptian children with Idiopathic Generalized Epilepsy (IGE). METHODS A cohort of 210 Egyptian children was divided into two groups for this case-control study: group (I) included 100 children with IGE, group (II) comprised of 110 paediatric healthy controls. PCR-RFLP was used to amplify the C588 T polymorphism of the GABARG2 gene, which was digested with APOI restriction enzymes. RESULTS There was a higher frequency of the TT genotype (P = 0.004) and T allele (P = 0.002) of the C588 T polymorphism of the GABARG2 gene in patients than controls. Besides, there was a substantial increase of the T allele among drug-resistant patients compared with those responding to antiepileptic drugs (P = 0.00015). Children with the C allele were four times more likely to be responsive to antiepileptic drugs than non-C-allele-carriers. CONCLUSION The C588 T polymorphism of GABARG2 is associated with an increased risk of developing childhood IGE and may modulate patients' response to antiepileptic drugs.
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Association of GABAA Receptor Gene with Epilepsy Syndromes. J Mol Neurosci 2018; 65:141-153. [PMID: 29785705 DOI: 10.1007/s12031-018-1081-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/01/2018] [Indexed: 12/19/2022]
Abstract
GABA has always been an inviting target in the etiology and treatment of epilepsy. The GABRA1, GABRG2, and GABRD genes provide instructions for making α1, ϒ2, and δ subunits of GABAA receptor protein respectively. GABAA is considered as one of the most important proteins and has found to play an important role in many neurological disorders. We explored the association of GABAA receptor gene mutation/SNPs in JME and LGS patients in Indian population. A total of 100 epilepsy syndrome patients (50 JME and 50 LGS) and 100 healthy control subjects were recruited and analyzed by AS-PCR and RFLP-PCR techniques. In our study, GABRA1 965 C > A mutation and 15 A > G polymorphism gene may play an important role in modulating the drug efficacy in LGS patients. The GABRA1 15 A > G polymorphism may also play an important role in the susceptibility of LGS and the inheritance of GG genotype of this polymorphism may provide an increased risk of development of LGS. The GABRG2 588 C > T polymorphism may decrease the duration of seizures in JME patients. The GABRD 659 G > A polymorphism may play an important role in the susceptibility of JME and LGS and this polymorphism may also increase the duration of postictal period in JME patients but may decrease the duration of seizure in LGS patients.
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Butilă AT, Zazgyva A, Sin AI, Szabo ER, Tilinca MC. GABRG2 C588T gene polymorphisms might be a predictive genetic marker of febrile seizures and generalized recurrent seizures: a case-control study in a Romanian pediatric population. Arch Med Sci 2018; 14:157-166. [PMID: 29379546 PMCID: PMC5778423 DOI: 10.5114/aoms.2016.63739] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/14/2016] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION This case-control study aimed to assess two single nucleotide polymorphisms of the gene encoding the GABRG2 protein - GABRG2 (3145 G>A) and GABRG2 rs 211037 Asn196Asn (C588T) - in a cohort of pediatric patients from Romania, and evaluate their possible impact on drug-resistant forms of generalized epilepsy and recurrent febrile seizures. MATERIAL AND METHODS One hundred and fourteen children with idiopathic generalized epilepsy (group 1) or febrile seizures (group 2) were compared to 153 controls. Peripheral blood samples were assessed using polymerase chain reaction-restriction fragment length polymorphism analysis, with results interpreted based on the disappearance of a restriction site in the C allele (122 bp) compared to the T allele (100 bp + 22 bp). RESULTS A significant association was found with the TT homozygous genotype and T allele for both febrile seizures and epilepsy for the C588T locus, while GABRG2 G>A 3145 showed no significant association with any type of seizure. The TT homozygous genotype of GABRG2 Asn196Asn polymorphism was more frequent in patients with a history of febrile seizures (p = 0.0001), without a significant association identified for GABRG2-G>A 3145. Composite analysis showed associations with epilepsy for CC-AG (p = 0.02) and CT-AG (p = 0.007) with the CC-AA combination as reference. CONCLUSIONS C588T polymorphism of the GABRG2 gene might be a predictive genetic marker in triggering febrile convulsions. GABRG2 rs211037 TT homozygotes and T allele variants have an increased risk for developing febrile seizures. Recurrent crises and repeated episodes of seizures are more frequent in the GABRG2 Asn196Asn TT genotype polymorphism, with a 45 and 8 times higher risk of developing idiopathic generalized epilepsy and recurrent febrile seizures, respectively.
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Affiliation(s)
- Anamaria Todoran Butilă
- Department of Genetics, University of Medicine and Pharmacy of Târgu-Mureş, Târgu-Mureş, Romania
| | - Ancuta Zazgyva
- Department of Cell and Molecular Biology, University of Medicine and Pharmacy of Târgu-Mureş, Târgu-Mureş, Romania
| | - Anca Ileana Sin
- Department of Cell and Molecular Biology, University of Medicine and Pharmacy of Târgu-Mureş, Târgu-Mureş, Romania
| | - Elisabeta Racoș Szabo
- Department of Psychiatry, University of Medicine and Pharmacy of Târgu-Mureş, Târgu-Mureş, Romania
| | - Mariana Cornelia Tilinca
- Department of Cell and Molecular Biology, University of Medicine and Pharmacy of Târgu-Mureş, Târgu-Mureş, Romania
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Lim KS, Ng CC, Chan CK, Foo WS, Low JSY, Tan CT. Ethnic variation of genetic (idiopathic) generalized epilepsy in Malaysia. Seizure 2017; 45:24-27. [DOI: 10.1016/j.seizure.2016.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/19/2016] [Accepted: 11/17/2016] [Indexed: 10/20/2022] Open
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In Silico Prediction of Gamma-Aminobutyric Acid Type-A Receptors Using Novel Machine-Learning-Based SVM and GBDT Approaches. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2375268. [PMID: 27579307 PMCID: PMC4992803 DOI: 10.1155/2016/2375268] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 06/08/2016] [Accepted: 06/19/2016] [Indexed: 11/17/2022]
Abstract
Gamma-aminobutyric acid type-A receptors (GABAARs) belong to multisubunit membrane spanning ligand-gated ion channels (LGICs) which act as the principal mediators of rapid inhibitory synaptic transmission in the human brain. Therefore, the category prediction of GABAARs just from the protein amino acid sequence would be very helpful for the recognition and research of novel receptors. Based on the proteins' physicochemical properties, amino acids composition and position, a GABAAR classifier was first constructed using a 188-dimensional (188D) algorithm at 90% cd-hit identity and compared with pseudo-amino acid composition (PseAAC) and ProtrWeb web-based algorithms for human GABAAR proteins. Then, four classifiers including gradient boosting decision tree (GBDT), random forest (RF), a library for support vector machine (libSVM), and k-nearest neighbor (k-NN) were compared on the dataset at cd-hit 40% low identity. This work obtained the highest correctly classified rate at 96.8% and the highest specificity at 99.29%. But the values of sensitivity, accuracy, and Matthew's correlation coefficient were a little lower than those of PseAAC and ProtrWeb; GBDT and libSVM can make a little better performance than RF and k-NN at the second dataset. In conclusion, a GABAAR classifier was successfully constructed using only the protein sequence information.
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Contribution of GABRG2 Polymorphisms to Risk of Epilepsy and Febrile Seizure: a Multicenter Cohort Study and Meta-analysis. Mol Neurobiol 2015; 53:5457-67. [DOI: 10.1007/s12035-015-9457-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 09/25/2015] [Indexed: 10/23/2022]
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Association of GABRA6 1519 T>C (rs3219151) and Synapsin II (rs37733634) gene polymorphisms with the development of idiopathic generalized epilepsy. Epilepsy Res 2014; 108:1267-73. [DOI: 10.1016/j.eplepsyres.2014.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 06/18/2014] [Accepted: 07/09/2014] [Indexed: 11/22/2022]
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Lee PC, Yang YY, Lin MW, Hou MC, Huang CS, Lee KC, Wang YW, Hsieh YC, Huang YH, Chu CJ, Lin HC. Benzodiazepine-associated hepatic encephalopathy significantly increased healthcare utilization and medical costs of Chinese cirrhotic patients: 7-year experience. Dig Dis Sci 2014; 59:1603-16. [PMID: 24482035 DOI: 10.1007/s10620-013-3021-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/30/2013] [Indexed: 01/16/2023]
Abstract
BACKGROUND AND OBJECTIVES In cirrhosis, hypersensitivity to benzodiazepines (BZD) and precipitating hepatic encephalopathy (HE) have been reported. The aim of this study was to evaluate the safety, economic impact and modifiable factors that are associated with the excess risk of BZD-associated HE in cirrhotic patients. METHODS Between July 2005 and March 2012, 1,612 Chinese cirrhotic patients with and without using long-t 1/2-BZD or short-t 1/2-BZD were enrolled and followed up for 6 months. RESULTS Among BZD users, the per-person HE-related healthcare utilization and medical costs were found to have progressively increased from 2005 to 2012. Cirrhotic BZD users had a higher percentage of smoking, alcohol drinking, simultaneous consumption of non-BZD drugs, and had a higher incidence of non-cirrhotic chronic illness than non-BZD users. Multivariate analysis indicated that hypoalbuminemia (<3 g/dL), long-acting (t 1/2 > 12-h), high-dosage (>1.5 defined daily dose equivalents) and long-duration (>2-months) BZD use, carrier of variant genotypes (AG + GG) of GABRA 1 (rs2290732) and having the wild genotype (TT) of GABRG 2 (rs211037) were significant predictors of the development of BZD-associated HE in cirrhotic patients. Additionally, synergistic effects of the above significant predictors on BZD-associated HE risk could be identified. CONCLUSIONS Our study confirms the clinical and economic impact of BZD-associated HE in cirrhotic BZD-users. Accordingly, extra caution is needed when treating cirrhotic BZD users with the above risk factors in order to avoid the BZD-associated HE in cirrhotic patients.
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Affiliation(s)
- Pei-Chang Lee
- Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
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Hung CC, Chen PL, Huang WM, Tai JJ, Hsieh TJ, Ding ST, Hsieh YW, Liou HH. Gene-wide tagging study of the effects of common genetic polymorphisms in the α subunits of the GABA(A) receptor on epilepsy treatment response. Pharmacogenomics 2014; 14:1849-56. [PMID: 24236484 DOI: 10.2217/pgs.13.158] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM We aimed to identify the effect of SNPs in the α-subunits of GABAA receptors on epilepsy treatment outcomes by using a gene-wide tagging method. MATERIALS & METHODS There were 720 epileptic patients included in the present study. A total of 136 tagging SNPs in GABRA1, GABRA2, GABRA3, GABRA4, GABRA5 and GABRA6 were genotyped by Illumina(®)GoldenGate(®) Genotyping platform. Clinical information, such as prescribed antiepileptic drugs, height, weight, epilepsy syndrome classification, etiology, number of attacks, renal function and liver function were collected. The associations between SNPs and epilepsy treatment outcomes were analyzed using SAS(®) version 9.1.3. Both multivariate logistic regression and multifactor dimensionality reduction analyses were performed. RESULTS The results of single gene effects did not remain significant after Bonferroni's corrections. Further multivariate logistic regression and multifactor dimensionality reduction analyses of interactions between these genes showed that under adjustment of clinical factors, the epilepsy treatment outcomes were significantly associated with the genotype combinations of GABRA1 rs6883877, GABRA2 rs511310 and GABRA3 rs4828696 (p < 0.0001; adjusted r(2) = 0.149). CONCLUSION Our results indicated that genetic variants in the α subunits of GABA(A) receptors may interactively affect the treatment responses of antiepileptic drugs. Further replication using an independent sample collection would be essential to confirm our findings.
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Affiliation(s)
- Chin-Chuan Hung
- Department of Pharmacy, College of Pharmacy, China Medical University, Taichung, Taiwan and Department of Pharmacy, China Medical University Hospital, Taichung, Taiwan
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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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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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Yilmaz M, Edgunlu TG, Yilmaz N, Cetin ES, Celik SK, Emir GK, Sözen A. Genetic variants of synaptic vesicle and presynaptic plasma membrane proteins in idiopathic generalized epilepsy. J Recept Signal Transduct Res 2013; 34:38-43. [PMID: 24164654 DOI: 10.3109/10799893.2013.848893] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The aim of this study was to analyze the role of the genetic variants of two synaptic vesicle proteins (VAMP2 and Synaptotagmin XI) and two presynaptic plasma membrane proteins (Syntaxin 1A and SNAP-25) in patients with idiopathic generalized epilepsy (IGE). METHOD Eighty-five patients with IGE and 93 healthy subjects were included in the study. We analyzed the functional polymorphisms of VAMP2, Synaptotagmin XI, Syntaxin 1A and SNAP-25 genes with polymerase chain reaction and restriction fragment length polymorphism methods. RESULTS In the patients with IGE, significant differences alleles and genotypes of 26 bp Ins/Del polymorphism of the VAMP2 gene and the 33-bp promoter region of Synaptotagmin XI were observed, however no associaton was found regarding Intron 7 rs1569061 of Syntaxin 1A gene, MnlI rs3746544 and DdeI rs1051312 polymorphisms of SNAP-25 gene compared with healthy subjects. Carriers of the C allele of Synaptotagmin XI had worse measures compared with the T allele of Synaptotagmin XI. In the haplotype analysis, the frequency of the T alleles of rs1569061 and of the C alleles of the 33-bp promoter region of Synaptotagmin XI was found to be significantly higher in patients with IGE as compared with the healthy subjects. CONCLUSION The genetic variations of VAMP2, Synaptotagmin XI might be indication of the relationship between these genes and IGE.
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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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Salam SMA, Rahman HMA, Karam RA. GABRG2 gene polymorphisms in Egyptian children with simple febrile seizures. Indian J Pediatr 2012; 79:1514-6. [PMID: 21983990 DOI: 10.1007/s12098-011-0564-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 09/19/2011] [Indexed: 11/28/2022]
Abstract
Mutations in the gamma-aminobutyric acid type A receptor (GABRG2) gene have been associated with generalized epilepsy, childhood absence epilepsy and febrile seizures. In the present study the authors investigated the association of polymorphism of the GABRG2 with simple febrile seizures (FS) in Egyptian children. Polymorphism at GABRG2 (SNP211037, Asn196Asn), on chromosome 5q33 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 100 Egyptian children with simple FS, and 120 healthy controls. The frequency of CC genotype of GABRG2 gene was significantly higher in children with simple FS compared to healthy children (p ≤ 0.0001). The C allele of GABRG2 was associated with increased risk for developing simple FS (OR: 2.15. 95% CI, 1.4-3.2. p ≤ 0.0001). The present findings suggested that the GABRG2 (SNP211037)-C allele could be a suitable genetic marker for prediction of susceptibility to simple FS in Egyptian children.
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Affiliation(s)
- Sanaa M Abdel Salam
- Department of Pediatrics, Faculty of medicine, Zagazig University, Zagazig, Egypt.
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Ponnala S, Chaudhari JR, Jaleel MA, Bhiladvala D, Kaipa PR, Das UN, Hasan Q. Role of MDR1 C3435T and GABRG2 C588T gene polymorphisms in seizure occurrence and MDR1 effect on anti-epileptic drug (phenytoin) absorption. Genet Test Mol Biomarkers 2012; 16:550-7. [PMID: 22239287 DOI: 10.1089/gtmb.2011.0225] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
AIMS To assess the role of MDR1 and gamma-aminobutyric acid receptor-gamma 2 sub unit (GABRG2) gene polymorphism in seizure susceptibility in generalized seizure (GS) and febrile seizure (FS) patients and to evaluate MDR1 C3435T gene polymorphism's role in absorption of the anti-epileptic drug, phenytoin (PHT) in a cohort of patients. METHODS One hundred twenty-seven cases of seizure (86 GS and 41 FS) patients were analyzed for MDR1 C3435T and GABRG2 C588T gene polymorphisms using restriction fragment length polymorphism-polymerase chain reaction. Serum PHT levels were analyzed. RESULTS The T allele of MDR1 C3435T and GABRG2 C588T gene polymorphism was higher in GS in the Indian population compared with controls. From the data in GS, CT and TT genotype carriers of the MDR1 gene and TT genotype carriers of the GABRG2 gene had more recurrent seizures compared with others. MDR1 T allele carriers in the seizure reoccurrence (SR) group of GS and FS were high compared with the well-controlled seizure group (with no seizures after treatment). TT genotype carriers in SR group were high in FS (with regard to MDR1 gene polymorphism) and GS (with regard to GABRG2 gene polymorphism) compared with a well-controlled seizure group. MDR1 C3435T gene polymorphism affects serum PHT levels (p<0.015). Association of dose PHT ratio and genotype groups of MDR1 C3435T gene polymorphism showed a significant association (p<0.05). MDR1*CC genotype was more common in cases with low serum PHT levels.In addition, it is evident that CT and TT genotype carriers have a high percentage of SR with elevated serum PHT levels. CONCLUSIONS Our results show that the MDR1 3435T and GABRG2 588T alleles play a role in seizure occurrence. Moreover, the MDR1 3435T allele also affects PHT absorption. We suggest MDR1 C3435T and GABRG2 C588T genotyping would be of value in order to lower the risk of concentration-dependent drug toxicity and for better patient management.
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Affiliation(s)
- Shivani Ponnala
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, USA.
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Kumari R, Lakhan R, Garg RK, Kalita J, Misra UK, Mittal B. Pharmacogenomic association study on the role of drug metabolizing, drug transporters and drug target gene polymorphisms in drug-resistant epilepsy in a north Indian population. INDIAN JOURNAL OF HUMAN GENETICS 2011; 17 Suppl 1:S32-40. [PMID: 21747585 PMCID: PMC3125053 DOI: 10.4103/0971-6866.80357] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND: In epilepsy, in spite of the best possible medications and treatment protocols, approximately one-third of the patients do not respond adequately to anti-epileptic drugs. Such interindividual variations in drug response are believed to result from genetic variations in candidate genes belonging to multiple pathways. MATERIALS AND METHODS: In the present pharmacogenetic analysis, a total of 402 epilepsy patients were enrolled. Of them, 128 were diagnosed as multiple drug-resistant epilepsy and 274 patients were diagnosed as having drug-responsive epilepsy. We selected a total of 10 candidate gene polymorphisms belonging to three major classes, namely drug transporters, drug metabolizers and drug targets. These genetic polymorphism included CYP2C9 c.430C>T (*2 variant), CYP2C9 c.1075 A>C (*3 variant), ABCB1 c.3435C>T, ABCB1c.1236C>T, ABCB1c.2677G>T/A, SCN1A c.3184 A> G, SCN2A c.56G>A (p.R19K), GABRA1c.IVS11 + 15 A>G and GABRG2 c.588C>T. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods, and each genotype was confirmed via direct DNA sequencing. The relationship between various genetic polymorphisms and responsiveness was examined using binary logistic regression by SPSS statistical analysis software. RESULTS: CYP2C9 c.1075 A>C polymorphism showed a marginal significant difference between drug resistance and drug-responsive patients for the AC genotype (Odds ratio [OR] = 0.57, 95% confidence interval [CI] = 0.32–1.00; P = 0.05). In drug transporter, ABCB1c.2677G>T/A polymorphism, allele A was associated with drug-resistant phenotype in epilepsy patients (P = 0.03, OR = 0.31, 95% CI = 0.10-0.93). Similarly, the variant allele frequency of SCN2A c.56 G>A single nucleotide polymorphism was significantly higher in drug-resistant patients (P = 0.03; OR = 1.62, 95% CI = 1.03, 2.56). We also observed a significant difference at the genotype as well as allele frequencies of GABRA1c.IVS11 + 15 A > G polymorphism in drug-resistant patients for homozygous GG genotype (P = 0.03, OR = 1.84, 95% CI = 1.05–3.23) and G allele (P = 0.02, OR = 1.43, 95% CI = 1.05–1.95). CONCLUSIONS: Our results showed that pharmacogenetic variants have important roles in epilepsy at different levels. It may be noted that multi-factorial diseases like epilepsy are also regulated by various other factors that may also be considered in the future.
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Affiliation(s)
- Ritu Kumari
- Department of Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
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Kumari R, Lakhan R, Kalita J, Misra U, Mittal B. Association of alpha subunit of GABAA receptor subtype gene polymorphisms with epilepsy susceptibility and drug resistance in north Indian population. Seizure 2010; 19:237-41. [DOI: 10.1016/j.seizure.2010.02.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 02/21/2010] [Accepted: 02/26/2010] [Indexed: 11/26/2022] Open
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Lagae L. What's new in: "genetics in childhood epilepsy". Eur J Pediatr 2008; 167:715-22. [PMID: 18320221 DOI: 10.1007/s00431-008-0690-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 02/06/2008] [Indexed: 12/17/2022]
Abstract
In recent years, different mutations in genes that control the excitability of neurons have been described in idiopathic childhood epilepsies. Most commonly, sodium/potassium channelopathies and GABA-receptor mutations are involved. Major progress has been made in the field of idiopathic generalised epilepsies associated with febrile seizures (GEFS+). It now is becoming clear that mutations should not only be looked for in familial cases, but also in sporadic cases, especially in infants and young children with unexplained severe epileptic encephalopathies. Many studies also define 'epilepsy susceptibility genes', which contribute to one's individual genetic vulnerability to develop epilepsy. It should be realized, however, that in the most common idiopathic benign childhood epilepsies (benign rolandic and occipital epilepsies), major breakthroughs are still awaited. In addition, a better clinical description of the epileptic phenotypes is needed to explain more precisely the genotypic and phenotypic heterogeneity. Genetic studies are nowadays becoming a necessary diagnostic step in the evaluation of idiopathic childhood epilepsies, not only in familial cases, but also in sporadic cases.
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Affiliation(s)
- Lieven Lagae
- Department of Paediatric Neurology, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
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Abstract
Genetic influences as causal factors in the epilepsies continue to be vigorously investigated, and we review several important studies of genes reported in 2006. To date, mutations in ion channel and neuroreceptor component genes have been reported in the small fraction of cases with clear Mendelian inheritance. These findings confirm that the so-called "channelopathies" are generally inherited as monogenic disorders. At the same time, the literature in common epilepsies abounds with reports of associations and reports of nonreplication of those association studies, primarily with channel genes. These contradictory reports can mostly be explained by confounding factors unique to genetic studies. The methodology of genetic studies and their common biases and confounding factors are also explained in this review. Amid the controversy, steady progress is being made on the epilepsies of complex inheritance, which represent the most common idiopathic epilepsy. Recent discoveries show that genes influencing the developmental assembly of neural circuits and neuronal metabolism may play a more prominent role in the common epilepsies than genes affecting membrane excitability and synaptic transmission.
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Affiliation(s)
- David A Greenberg
- Division of Statistical Genetics, Mailman School of Public Health, Columbia University Medical Center, 122 West 168th Street, 6th Floor, New York, NY 10032, USA.
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