title: Association of gamma-aminobutyric acid A receptor α2 gene (GABRA2) with alcohol use disorder.
abstract: Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in mammalian brain. GABA receptor are involved in a number of complex disorders, including substance abuse. No variants of the commonly studied GABA receptor genes that have been associated with substance dependence have been determined to be functional or pathogenic. To reconcile the conflicting associations with substance dependence traits, we performed a meta-analysis of variants in the GABAA receptor genes (GABRB2, GABRA6, GABRA1, and GABRG2 on chromosome 5q and GABRA2 on chromosome 4p12) using genotype data from 4739 cases of alcohol, opioid, or methamphetamine dependence and 4924 controls. Then, we combined the data from candidate gene association studies in the literature with two alcohol dependence (AD) samples, including 1691 cases and 1712 controls from the Study of Addiction: Genetics and Environment (SAGE), and 2644 cases and 494 controls from our own study. Using a Bonferroni-corrected threshold of 0.007, we found strong associations between GABRA2 and AD (P=9 × 10(-6) and odds ratio (OR) 95% confidence interval (CI)=1.27 (1.15, 1.4) for rs567926, P=4 × 10(-5) and OR=1.21 (1.1, 1.32) for rs279858), and between GABRG2 and both dependence on alcohol and dependence on heroin (P=0.0005 and OR=1.22 (1.09, 1.37) for rs211014). Significant association was also observed between GABRA6 rs3219151 and AD. The GABRA2 rs279858 association was observed in the SAGE data sets with a combined P of 9 × 10(-6) (OR=1.17 (1.09, 1.26)). When all of these data sets, including our samples, were meta-analyzed, associations of both GABRA2 single-nucleotide polymorphisms remained (for rs567926, P=7 × 10(-5) (OR=1.18 (1.09, 1.29)) in all the studies, and P=8 × 10(-6) (OR=1.25 (1.13, 1.38)) in subjects of European ancestry and for rs279858, P=5 × 10(-6) (OR=1.18 (1.1, 1.26)) in subjects of European ancestry. Findings from this extensive meta-analysis of five GABAA receptor genes and substance abuse support their involvement (with the best evidence for GABRA2) in the pathogenesis of AD. Further replications with larger samples are warranted.
authors.affiliation: 1] Department of Psychiatry, School of Medicine, Yale University, New Haven, CT, USA [2] Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA [3] Department of Computer Science, University of Vermont, Burlington, VT, USA [4] Neuroscience, Behavior, and Health Initiative, University of Vermont, Burlington, VT, USA.
authors.forename: Dawei
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA.
authors.forename: Arvis
authors.initials: A
authors.lastname: Sulovari
authors.affiliation: Department of Genetics, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA.
authors.forename: Chao
authors.initials: C
authors.lastname: Cheng
authors.affiliation: 1] Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA [2] Department of Genetics, School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Psychiatry, Perelman School of Medicine of the University of Pennsylvania and Philadelphia VAMC, Philadelphia, PA, USA.
authors.forename: Henry R
authors.initials: HR
authors.lastname: Kranzler
authors.affiliation: 1] Department of Psychiatry, School of Medicine, Yale University, New Haven, CT, USA [2] Department of Genetics, School of Medicine, Yale University, New Haven, CT, USA [3] VA Connecticut Healthcare Center, West Haven, CT, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Gelernter
mesh_terms: D000437:Alcoholism / Q000208:ethnology / Q000235:genetics*; D044383:Black People; D019295:Computational Biology; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011963:Receptors, GABA-A / Q000235:genetics*; D012016:Reference Values; D012189:Retrospective Studies; D044465:White People
chemical_list: C484841:GABRA2 protein, human; D011963:Receptors, GABA-A