Association of the Serotonin Transporter Gene With Smoking Behavior

OBJECTIVE: In an ongoing molecular genetic study of temperament, participants were genotyped to examine the association of smoking with two polymorphisms of the serotonin transporter gene (SERT): the promoter region, 5-HTTLPR, and an intronic variable-number-of-tandem-repeats region (VNTR). METHOD: Full information was available for 330 families, and 244 “ever smokers” were identified (54 past smokers, 190 current smokers). The average number of cigarettes smoked per day was 13.12, and the mean Fagerstrom Tolerance Questionnaire score was 4.79. Associations of genotype, Tridimensional Personality Questionnaire scores, and smoking phenotype were tested by using a robust family design with a variance-components framework and by case-control analysis. RESULTS: There was a significant excess of the 5-HTTLPR long allele with the 12-repeat VNTR in current smokers, past smokers, and ever smokers, compared to participants who had never smoked. The results from the population design were confirmed in the family-ba...