Association of D2 dopamine receptor and alcohol dehydrogenase 2 genes withPolynesian alcoholics

Alleles of the D2 dopamine receptor (DRD2) and the alcohol dehydrogenase 2 (ADH2) genes were determined in 69 French Polynesian alcoholic patients and 57 controls matched for racial origin. Three racial groups were studied: p ure Polynesians (PP), Polynesians mixed with Callcasian (PGA) ancestry and Polynesians mixed with Chinese (PCH) ancestry. DRD2 Al allele frequencies i n the alcoholics compared to their controls in these groups were: PP, .26 v s .32 (P = .69); PGA, .44 vs .35 (P = .46); PCH, .40 vs 0.39 (P = .88). ADH 2 1 allele frequencies in alcoholics compared to their controls groups were : PP, .56 vs .62 (P = .66); PCA, .75 vs .56 IP = .09); PCH, .78 vs .32 IP = .009). In the PCA group, the combination of the DRDP Al genotypes and the ADH2 1 homozygotes was strongly associated with alcoholism (P = .0027). Thi s preliminary study shows the importance of ascertaining racial ancestry in molecular genetic association studies. Moreover, it suggests that a combin ation of genes are involved in susceptibility to the development of alcohol ism. (C) 2000 Editions scientifiques et medicales Elsevier SAS.