An association study of catechol-O-methyltransferase and monoamine oxidase A polymorphisms and personality traits in Koreans

Catechol-O-methyltransferase (COMT) and monoamine oxidase A (MAOA) are both involved in the degradation of various biogenic amines which have been hypothesized to have a relationship with personality traits. The present study investigated the possible relationships between the genotypes of COMT Val158Met and MAOA-uVNTR polymorphisms and personality traits measured by the Temperament and Character Inventory (TCI). We recruited 286 normal, unrelated Korean subjects (138 males and 148 females). There were no associations between the COMT Val158Met genotypes or the TCI subscales in the male subjects. However, a significant correlation was observed between the COMT genotype and harm avoidance (HA, F = 6.0, p = 0.003) in females. Post hoc analyses showed that the subjects with the Met/Met genotype had the lowest mean HA (HA = 13.8 ± 5.7, p = 0.02), Val/Met group had an intermediate mean HA score (HA = 16.3 ± 7.0, p = 0.02), and Val/Val group had the highest mean HA value (HA = 19.6 ± 7.0, p = 0.02). There were no associations between the MAOA-uVNTR and the TCI subscales in either the male or female subjects. These results suggest that genetic variants of the COMT Val158Met gene may play a role in HA in Korean females but not in males.