Epistatic effect of Ankyrin repeat and kinase domain containing 1 - Dopamine receptor D2 and catechol-o-methyltransferase single nucleotide polymorphisms on the risk for hazardous use of alcohol in Lithuanian population.

Abstract

The Lithuanian population has outstanding rates of alcohol consumption and alcohol related mortality. Alteration of brain dopaminergic system play a role in the risk for addiction disorders. We evaluated the association of one single nucleotide polymorphism rs1800497 in the Ankyrin Repeat and Kinase Domain Containing 1 - Dopamine Receptor D2 complex (ANKK1-DRD2) and a catechol-o-methyltransferase (COMT) rs4680 single nucleotide polymorphism with the risk for alcohol use disorder and impulsiveness in Lithuanian population. Both genetic polymorphisms are known to alter brain dopaminergic activity, thus we also investigated the possible interaction effect of these polymorphisms. The study included 329 participants recruited from the local community. Hazardous alcohol use was evaluated using the Alcohol Use Disorder Identification Test (AUDIT). Impulsiveness was measured using the Barratt Impulsiveness Scale - 11 (BIS-11). Between group differences of AUDIT and BIS-11 scores were examined stratified by genetic polymorphisms and their combinations. The independent effect of each polymorphism and their interaction for hazardous alcohol use were evaluated using adjusted logistic regression analyses. The ANKK1-DRD2 rs1800497 polymorphism was associated with total AUDIT score, but not with the hazardous use of alcohol, as indicated by the AUDIT test cut-off of 8. The COMT rs4680 GG genotype was associated with the hazardous use of alcohol (adjusted OR=2.094, p=0.029), but this association was not statistically significant after adjustment for multiple comparisons. Presence of both COMT rs4680 and ANKK1-DRD2 rs1800497 GGxCT/TT polymorphisms was associated with significantly increased risk for hazardous use of alcohol (adjusted OR=5.016, p=0.005). The COMT rs4680 and ANKK1-DRD2 rs1800497 genetic polymorphisms, and their combination were not associated with impulsiveness. Our study demonstrated that the interaction of COMT rs4680 and ANKK1-DRD2 rs1800497 genetic polymorphisms is associated with a hazardous use of alcohol.