Association and family studies of DRD2 gene polymorphisms in alcohol dependence syndrome.

INTRODUCTION The human dopamine receptor 2 gene DRD2 plays a central role in susceptibility to Alcohol Dependence Syndrome (ADS). The aim of this study was to evaluate 3 single nucleotide polymorphisms: D2 (rs1076560), Tag1D (rs1800498), Tag1B (rs1079597) located in dopamine receptor 2 DRD2 gene and its role in alcohol dependence. MATERIAL AND METHODS DNA was provided from alcohol dependent (AD) patients (n=171) and healthy control subjects (n=160) all of Polish descent. The history of alcoholism was obtained using the Polish version of the SSAGA (Semi-Structured Assessment for the Genetics of Alcoholism). We conducted case-control association study and transmission disequilibrium test (TDT). Samples were genotyped using real-time PCR method. RESULTS We did not confirm the association between studied polymorphisms and alcohol dependence syndrome. TDT reveled an adequate transmission of both alleles in the group of alcohol families. CONCLUSIONS The lack of association of studied polymorphisms and ADS does not preclude its participation in the pathogenesis. Further research is needed to determine the actual contribution of DRD2 gene in the pathogenesis of alcoholism.