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

Indications of a genetic predisposition to nicotine dependence have been derived from numerous epidemiological data and from individual genetic studies suggesting the involvement of the dopaminergic D2 receptor. Previous association studies defined the TaqlA polymorphism as a risk factor for addiction, in particular for alcoholism and tobacco dependence. Results of investigations into this polymorphism in 110 severely addicted smokers and a control group of 60 population-matched German non-smokers did not support these findings. However, our results indicate an association between the DRD2-Fokl-1 allele and the onset and intensity of smoking.