Too much alcohol, different gene surface? Alcohol abuse could be associated with monoamine oxidase A gene methylation

Abstract

Monoamine oxidase A (MAO-A) is an enzyme that metabolizes neurotransmitters involved in alcohol dependency. To investigate if MAO-A is associated with alcohol abuse, I compared MAOA gene methylation in males with or without alcohol use disorders (N = 24 and N = 55, respectively). Methylation of MAOA gene in white blood cells was used as an index of MAO-A activity in the brain. Average methylation was higher in males with alcohol use disorders (AUD), but only in the nonsmokers’ subsample (Wilcoxon p = 0.01, proportion of better responses = 0.86). Methylation at gene site CpG10 was also higher in nonsmokers with AUD (p = 0.05, proportion = 0.80). Interaction between smoking and methylation is a novel finding. Because the sample of nonsmokers is small (N = 5 + 19), these results should be considered only as initial.