Association between Monoamine Oxidase A Polymorphisms and Anger-Related Personality Traits in Korean Women

It has been suggested that polymorphisms in the monoamine oxidase A (MAO-A) gene are associated with aggressive and impulsive behaviors. In the present study, we investigated the association of the MAO-A variable number of tandem repeat polymorphism in the promoter region (MAO-A uVNTR) with anger-related personality traits. Specifically, MAO-A uVNTR polymorphisms were examined for associations with the State-Trait Anger Expression Inventory (STAXI) scores in 211 normal Korean women. All subjects were assessed using the STAXI and genotyped for MAO-A uVNTR status. The scores on the STAXI subscales differed significantly among the MAO-A uVNTR polymorphism genotypes in terms of anger expression-out (AX-Out) scores. Post hoc comparisons revealed significant differences between the 3/3 and 4/4, and between 3/4 and 4/4 polymorphisms. However, no significant difference was observed in other STAXI subscale scores among these genotypes. Subjects with the high-activity MAO-A uVNTR had significantly higher AX-Out scores than subjects with other genotypes. MAO-A uVNTR polymorphisms may contribute in part to the expression of anger. These findings support the hypothesis that this polymorphism in the MAO-A gene may be associated with anger-related personality traits in Korean women.