No association of dopamine receptor sensitivity in vivo with genetic predisposition for alcoholism and DRD2/DRD3 gene polymorphisms in alcohol dependence

This study sought to examine dopamine receptor sensitivity among alcoholics in vivo and to explore whether this sensitivity might be associated with functional variations of dopamine D2 (DRD2) and D3 (DRD3) receptor genes along with a genetic predisposition for alcoholism as reflected by an alcohol-dependent first-degree relative. We analyzed the -141C Ins/Del polymorphism in the promoter region of the DRD2 gene and the Ser(9)Gly (BalI) polymorphism in exon 1 of the DRD3 gene in 74 alcohol-dependent Caucasian men with or without genetic predisposition for alcoholism. In vivo dopamine receptor sensitivity was assessed by measuring apomorphine-induced growth hormone release. A three-way analysis of variance revealed no significant effects of DRD2, DRD3 genotypes and genetic predisposition on dopamine receptor sensitivity. 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.