The dopamine D2 receptor (DRD2) gene - a genetic risk factor in heavy smoking?

Indications of a genetic predisposition to nicotine dependence have been de rived from numerous epidemiological data and from individual genetic studie s suggesting the involvement of the dopaminergic D2 receptor. Previous asso ciation studies defined the TaqlA polymorphism as a risk factor for addicti on, in particular for alcoholism and tobacco dependence. Results of investi gations into this polymorphism in 110 severely addicted smokers and a contr ol group of 60 population-matched Ger man non-smokers did not support these findings. However, our results indicate an association between the DRD2-Fo kl-1 allele and the onset and intensity of smoking.