Modulation of a number of genes on personality traits in a sample of healthy subjects.

A large number of studies investigated the genetic modulation of personality with mixed results. As a confirmatory analysis of previous findings, we firstly examined the association between several previously examined single nucleotide polymorphisms (SNPs) and personality traits in a sample of 158 healthy subjects. As a secondary aim, we tested the potential modulation of additional never previously investigated genes on personality. A blood sample was collected and the Temperament and Character Inventory (TCI) has been administered to all participants. Multivariate analysis of covariance, controlling for sex and age, was used to test SNP influence on TCI scores. Examination of previously studied gene variants showed an effect of adrenergic alpha 2B receptor (ADRA2B) on Cooperativeness and of serotonin receptor HTR2A on Self Directedness. Examination of new variants revealed that sex hormone binding protein (SHBG) was associated with reward dependence. Moreover, several additional variants showed a tendency towards association with some TCI traits, confirming previous results. This study suggests that ADRA2B, HTR2A and SHBG genes may be involved in the modulation of personality in healthy subjects. The major limitation of this study was the small sample size.