Further Analyses of Genetic Association Between GRM8 and Alcohol Dependence Symptoms Among Young Adults

Abstract

Objective: The gene GRM8, a metabotropic glutamate receptor, has emerged as a gene of interest for its possible role in the development of alcohol dependence, with evidence of association with an electrophysiological endophenotype and level of response to alcohol as well as suggestive evidence of association with alcohol dependence. Method: The present study further investigated the association between GRM8 and alcohol dependence symptom counts among young adults using a new sample of individuals collected as part of the prospective sample (ages 18–26 years; N = 842) from the Collaborative Study on the Genetics of Alcoholism (COGA). Results: Two single-nucleotide polymorphisms were significantly associated with alcohol dependence in European Americans using the Nyholt corrected p value of .007: rs886003 (β = -.212, p = .0002) and rs17862325 (β = -.234, p < .0001), but not in African Americans, likely because of the lower power to detect association in this group. Conclusions: These results further implicate the role of glutamate receptor genes such as GRM8 in the development of alcohol dependence.