DAT1 gene polymorphism in alcoholism: a family-based association study.

BACKGROUND: The present study tests the hypothesis that the 9-repeat allele of the dopamine transporter gene (DAT1; SLC6A3) is more frequent in alcohol-dependent probands--and in particular those with severe withdrawal symptoms (seizures and/or delirium)--compared to nonalcoholics. METHODS: To avoid stratification effects, the family-based association approach of Falk and Rubinstein was used in our sample of 87 alcohol-dependent probands and their biological parents. RESULTS: By applying a family-based association approach, we were not able to detect significant association between allele 9 at DAT1 (SLC6A3) and alcoholism as well as between patients with or without severe withdrawal symptoms. CONCLUSIONS: Based on our data, the impact of the 9-repeat allele of the dopamine transporter gene in alcoholism and the severity of alcohol withdrawal symptoms is putatively not substantial.