THE DOPAMINE D-2 RECEPTOR (DRD2) GENE - A GENETIC RISK FACTOR IN SMOKING

Of a group of 312 non-Hispanic Caucasians who smoked at least one pack per day, had unsuccessfully attempted to stop smoking, and were free of alcohol or other drug dependence, 48.7% carried the A1 allele of th e DRD2 gene. This was significantly greater than the 25.9% prevalence in the 714 known non-Hispanic Caucasian controls without alcohol or dr ug abuse, p < 10(-8), and significantly greater than in a smaller set of our study controls. There was a significant, inverse relationship b etween the prevalence of the D(2)A1 allele and the age of onset of smo king, p = 0.02, and the maximum duration of time the smokers had been able to quit smoking on their own, p = 0.02. These results suggest the DRD2 gene is one of a multifactorial set of risk factors associated w ith smoking.