Association of Genetic Variants in Alcohol Dehydrogenase 4 With Alcohol Dependence in Brazilian Patients

OBJECTIVE: The authors evaluated the association of three functional promoter polymorphisms of the ADH4 gene with alcohol dependence. METHOD: DNA from 92 alcohol-dependent patients and 92 healthy comparison subjects was genotyped for all three polymorphisms. RESULTS: Variants at the –75 base-pair (bp) (C allele) and –159 bp (A allele) positions were associated with alcohol dependence. Individuals with haplotypes carrying both risk alleles showed an odds ratio of 2.9. CONCLUSIONS: These preliminary results suggest that ADH4 may play a role in the etiology of alcohol dependence. The association requires further study and replication but is functionally plausible and has a large effect size.