Alcoholism and gene polymorphisms related to central dopaminergic transmission in the Japanese population.

We examined the association between gene polymorphisms related to central dopaminergic transmission and alcoholism in the Japanese population. Polymorphic gene loci examined included those encoding the dopamine D2 receptor (NcoI site and Ser-Cys site), the dopamine D3 receptor (BalI site), the dopamine D4 receptor (48 bp tandem repeat) and the dopamine transporter (40 bp tandem repeat). The genotype distribution at the NcoI site in the dopamine D2 receptor gene differed significantly (p < 0.5) between alcoholic patients and control subjects. The frequency of 7 repeats at the 40 bp/DAT tended to be higher (p < 0.1), and that of 9 repeats tended to be lower (p < 0.1) in alcoholic patients than in control subjects. The possible effects of dopamine-related gene polymorphisms, which might predispose individuals to alcoholism, are discussed.