Family-based study of the association of the dopamine D2 receptor gene (DRD2) with habitual smoking

A recent study showed an association between the dopamine D2 receptor gene (DRD2) and smoking. The purpose of this study was to determine if the famil ial transmission of smoking is linked to variation at the DRD2 locus in a g enetically informative sample, Subjects were identified in alcohol treatmen t centers and their relatives were recruited for study. All subjects were i nterviewed to assess alcohol dependence, smoking habits, and psychiatric di sorders. Two polymorphisms within the DRD2 gene were analyzed, including th e TaqIA polymorphism. The sample consisted of 138 nuclear families with at least one offspring with habitual smoking, and analysis was by the transmis sion disequilibrium test (TDT), which avoids problems due to population str atification. There was no significant difference in the frequency between D RD2 alleles transmitted and not transmitted to habitual smokers, There also was no evidence for unequal transmission of DRD2 alleles for the phenotype s "ever smoker" or comorbid alcohol dependence and habitual smoking. This s tudy does not support linkage of the DRD2 with smoking. (C) 2000 Wiley-Liss , Inc.