Polymorphism of 5HT2A serotonin receptor gene is implicated in smoking addiction

Smoking behavior is influenced by genetic factors. Polymorphisms affecting the dopaminergic system have been linked to smoking habits. The aim of this study was to investigate if the T102C polymorphism of the 5-HT2A receptor gene is related to tobacco use, since this receptor modulates the mesolimbic dopamine system and the C allele is associated with reduced receptor gene expression. A sample of 625 subjects were geno-typed and classified according to their smoking behavior (never, former, or current smokers). We found differences in the distribution of the genotypes when the current smokers were compared with the never + former smokers, suggesting that T102C polymorphism is associated with maintenance, but not with initiation of the smoking habit. The CC genotype was more frequent in the current smokers than in the never + former smokers (chi(2) = 6.825, P = 0.03). The odds ratio of being a current smoker with a CC genotype was 1.63,95% CI 1.06-2.51. (C) 2004Wiley-Liss, Inc.