Previous studies have shown that the function of hypothalamic-pituitary-adrenal (HPA) axis is involved in the characterization of personality traits. Glucocorticoid receptor (GR) is the most important regulator of the HPA axis negative feedback system, and several polymorphisms of the GR gene are associated with altered glucocorticoid sensitivity. In the present study, we examined the associations between the GR polymorphisms and personality traits in healthy subjects.

Subjects were 880 Japanese healthy volunteers. Personality traits were assessed by the Temperament and Character Inventory (TCI). Two polymorphisms of the GR gene, i.e., G/C SNP in the intron 2 (BcII polymorphism, rs41423247) and A/G SNP in the exon 9β (9β polymorphism, rs6198), were detected by a real-time PCR and cycling probe technology for SNP typing.

The genotype distributions were G/G = 614, G/C = 240, and C/C = 26 for the BcII polymorphism, and A/A = 879 and A/G = 1 for the 9β polymorphism, respectively. There were no significant associations between the BcII genotype groups in any TCI dimension score.

The present study suggests that these two GR polymorphisms (BcII and 9β polymorphism) are not involved in the characterization of personality traits in healthy subjects.