ALLELIC ASSOCIATION OF THE D(2) DOPAMINE-RECEPTOR GENE WITH COCAINE DEPENDENCE

The objective of the present study was to examine allelic prevalence o f the D2 dopamine receptor (DRD2) gene in male cocaine-dependent (CD) Caucasian (non-Hispanic) subjects and to determine the relationship of DRD2 alleles to family history and selected behavioral measures. The prevalence of the A1 allele in CD subjects (n = 53) was 50.9%. It was significantly higher than either the 16.0% prevalence (P < 10(-4)) in non-substance abusing controls (n = 100) or the 30.9% prevalence (P < 10(-2)) in population controls (n = 265) wherein substance abusers wer e not excluded. Similarly, a significantly higher prevalence (p < 10(- 2)) of the B1 allele was found in CD subjects (n = 52) compared with n on-substance abusing controls (n = 53); 38.5% vs. 13.2%. Logistic regr ession analysis of CD subjects identified potent routes of cocaine use and the interaction of early deviant behaviors and parental alcoholis m as significant risk factors associated with the A1 allele. The cumul ative number of these three risk factors in CD subjects was positively and significantly (P < 10(-3)) related to A1 allelic prevalence. The data showing a strong association of the minor alleles (A1 and B1) of the DRD2 with cocaine dependence suggest that a gene, located on the q 22-q23 region of chromosome 11, confers susceptibility to this drug di sorder.