Role of allelic variants of FK506-binding protein 51 (FKBP5) gene in the development of anxiety disorders

Background Anxiety disorders exhibit remarkably high rates of comorbidity with major depressive disorder (MDD). Mood and anxiety disorders are considered stress-related diseases. Genetic variations in the co-chaperone FK506-binding protein 51, FKBP5, which modulates the function of glucocorticoid receptors, have been associated with an increased risk for the development of posttraumatic stress disorder, but data regarding its role in MDD are controversial. The aims of this study were to clarify the role of the FKBP5 gene in depression and anxiety disorders through a case-control study and an association study with personality traits using the Temperament and Character Inventory (TCI) in healthy subjects. Methods Six hundred fifty-seven MDD patients, with or without an anxiety disorder in comorbidity, and 462 healthy volunteers were enrolled in the study. Two hundred fifty-six controls agreed to fill out the TCI. Results The results showed that the T allele of rs1360780 was more frequent among the patients affected by MDD with a comorbidity of anxiety disorders, compared to those without (P <.001). Among the controls, we found that the T allele more often exhibited personality traits associated with an increased vulnerability to anxiety. Conclusions These results support the hypothesis that allelic variants of FKBP5 are a risk factor for anxiety disorders. The identification of genetic variants involved in anxiety may have implications for the optimization of therapeutic interventions.