Dopamine transporter gene polymorphism and alcoholism.

In this search for a possible association between the dopamine transporter gene (DAT1) polymorphism and alcoholism, 655 Japanese alcoholics were grouped according to their aldehyde dehydrogenase-2 (ALDH2) genotypes. Because inactive ALDH2 is an established negative risk factor for alcoholism, alcoholics with the mutant allele, ALDH22, were considered a relatively homogeneous group. The frequency of the 7-repeat allele of the DAT1 variable number of tandem repeat was significantly higher in alcoholics with ALDH22 than in control subjects. These results are consistent with the hypothesis that alteration in the dopaminergic system plays some role in the development of alcoholism.