Association study of the cytochrome P450 17 gene polymorphism with personality traits in healthy subjects.

There have been several studies suggesting that sex hormones are involved in characterization of human mental function and behaviour. Recently, it has been reported that the -34T/C polymorphism of cytochrome P450 17 (CYP17) gene affects sex hormone dispositions. Therefore, it is possible that the CYP17 -34T/C polymorphism affects personality traits. In the present study, the association of this genetic polymorphism with personality traits was examined in 595 healthy Japanese. Personality traits were assessed by the Temperament and Character Inventory (TCI), and the CYP17 -34T/C polymorphism was detected by a PCR-RFLP method. In males, the scores of novelty seeking, cooperativeness, and self-transcendence were higher in the group with the C allele than in that without this allele. In females, none of the seven TCI dimensions was different between the two genotype groups. The present study thus suggests that the -34T/C polymorphism of the CYP17 gene affects personality traits of healthy males, but not females, and this gender-dependent effect may be mediated by the action of sex hormones such as estradiol and testosterone.