[Genetic determinants of the alcohol dependence syndrome: searching for an endophenotype associated with sweet liking in families with alcohol addiction].

INTRODUCTION: The alcohol dependence syndrome is a disorder with a varying course of symptoms. Nevertheless, it is possible to distinguish subgroups of patients with a similar clinical picture. The purpose of this study was to determine the relationship between the sweet liking phenotype, a subtype of alcoholism according to Lesch and/or Cloninger and gene polymorphism of the DRD2 dopaminergic system.
MATERIAL AND METHODS: The study recruited 63 families (parents, alcohol-addicted son). Participants were interviewed for addiction (SSAGA, AUDIT) and were examined with the following questionnaires: MMSE, Beck Depression Inventory, Hamilton Anxiety Scale, and Lesch Typology Scale. Sensitivity to the sweet taste was tested and olfactometry was done. Polymorphism of the DRD2 gene was studied in exon 8, promoter region, and TaqI A1 locus.
RESULTS: There was no correlation between type of alcoholism and sucrose preference among alcoholics. A correlation (p = 0.048) between sweet liking in fathers and sons was found, as well as between sucrose preference in alcoholic probands and non-alcoholic fathers (p = 0.0378). Sucrose preference correlated with the TaqI A1 allele of the DRD2 gene among alcoholics (p = 0.0016). Changes in the distribution of alleles and genotypes of the TaqI DRD2 polymorphism correlated with sucrose preference among alcoholics (p = 0.008). Similar relationships were not observed for parents. There was no correlation between the hedonistic response to sucrose solutions and other polymorphisms of the DRD2 receptor gene in probands and parents.