ASSOCIATION OF FIVE POLYMORPHISMS IN THE GABA RECEPTOR GENES WITH TOBACCO AND ALCOHOL CONSUMPTION IN A SPANISH POPULATION

Evidence from animal and human research suggests that the Gamma amino butyric Acid (GABA) encephalic system is involved in drug addiction. Our aim is to assess the influence of genetic variations in GABA receptor genes on alcohol and tobacco consumption in a Spanish population. 763 unrelated individuals (465 women, 298 men) aged 18-85 years were recruited. Participants filled in a 35-item questionnaire on tobacco and alcohol consumption, the AUDIT and Fagerstrom tests. Individuals were genotyped for five polymorphisms in the GABRR2 and GABBR2 genes, using a TaqMan gamma (R) protocol. Carriers of the TT form at the rs282129 polymorphism showed an increased risk of being alcohol consumers (OR = 1.63; 95%CI: 1.13-2.64; p = 0.047). C carriers at the rs7865648 almost duplicated the risk of being an alcohol consumer (OR = 1.86; 95%CI: 1.19-2.90; p = 0.006) and also showed an increase in cigarette/day consumption (2.46 +/- 6.29 in C carriers as opposed to 3.64 +/- 7.77 in TT; p = 0.049). Finally, AA homozygotes for the rs6478676 polymorphism had a 3-fold increased risk of presenting a binge-drinking pattern (OR = 3.09; 95%CI: 1.49-6.38; p = 0.002). Thus, genetic variations in GABRR2 and GABBR2 genes may be associated with tobacco and alcohol consumption.