Association between dopamine receptor D2 genetic polymorphism TaqIA1 (C t) and susceptibility to alcohol dependence

Several studies are published, which investigated dopamine receptor 2 (DRD2) gene TaqIA polymorphism as ris factor for alcohol dependence (AD) with positive and negative association. To derive a more precise estimation of the relationship, a meta-analysis of case-control studies that examined the association between DRD2 gene Taq1A polymorphism and alcohol dependence were performed. Eligible articles were identified through search of databases including PubMed, Science Direct, Springer link and Google Scholar. The association between the DRD2 TaqIA polymorphism and AD susceptibility was conducted using odds ratios (ORs) and 95 % confidence intervals (95 % CIs) as association measure. A total of 69 studies with 9,125 cases and 9,123 healthy controls were included in current meta-analysis. Results of present analysis showed significant association between DRD2 TaqIA polymorphism and AD risk using a five genetic modes (allele contrast model -OR=1.22, 95% CI=1.13-1.32, p<0.0001; homozygote model -OR= 1.35, 95%CI= 1.18-1.55; p= <0.0001; dominant model -OR= 1.29; 95%CI= 1.20-1.39; p<0.0001; recessive model-OR= 1.21; 95%CI= 1.08-1.36; p= 0.0006). There was no significant association found between In subgroup analysis, TaqIA polymorphism was not significantly associated with AD risk in Asian population under all genetic models, but in Caucasian population TaqIA polymorphism was significantly associated with AD risk. Overall, results support the hypothesis that DRD2 Taq1A polymorphism plays a role in alcohol dependence.