Although the DRD3 rs6280 (Ser9Gly) polymorphism plays an important role in various psychiatric disorders, findings regarding the association between this single-nucleotide polymorphism (SNP) and alcohol dependence (AD) have been inconsistent.
In the absence of genetic data from Indian population, we evaluated genetic association of three polymorphisms namely rs4532 in DRD1, rs6280 in DRD3 and 120 bp duplication in 1.2 kb upstream region of DRD4 with AD.
Given the explorative and preliminary character of this investigation, we cannot provide evidence that in alcohol-dependent Caucasian men a genetic predisposition for alcoholism along with functional variants of the DRD2 and DRD3 genes are associated with differences in dopamine receptor sensitivity.
We made the hypothesis that phenotypical heterogeneity of alcohol-dependence (i.e. the DRD3 gene is a vulnerability gene in a specific subgroup of patients only) could explain these spurious findings, focusing on a core dimension of addictive disorders, namely impulsiveness.