Genetics of glucocorticoid regulation and posttraumatic stress disorder--What do we know?

CASTRO-VALE, I., E.F.C. van Rossum, J.C. Machado, R. Mota-Cardoso and D. Carvalho. Genetics of glucocorticoid regulation and posttraumatic stress disorder-What do we know? NEUROSCI. BIOBEHAV. REV. 43 (1) XXX-XXX, 2014 - Posttraumatic stress disorder (PTSD) develops in a small proportion of those who have been exposed to a traumatic event. Genetic factors are estimated to be responsible for 30% of the variance in PTSD risk. Dysfunction of the hypothalamic-pituitary-adrenal (HPA)-axis in PTSD has been found, particularly hypersensitivity of the glucocorticoid receptor (GR). In this review we aim to understand the genetic factors that influence glucocorticoid function in PTSD. Glucocorticoid action is regulated by a corticotrophin-releasing hormone, arginine vasopressin (AVP)/oxytocin pathway, GR, and regulators such as co-chaperone FKBP5. Single nucleotide polymorphisms (SNPs) in the GR gene, CRHR1 gene and FKBP5 gene affect HPA-axis sensitivity. The GR gene SNP BclI has been associated with hypersensitivity to glucocorticoids and PTSD symptoms. FKBP5 gene SNPs interacted with childhood adversity to moderate PTSD risk and in particular, the rs9470080 SNP was independently associated with lifetime PTSD. SNPs in the CRHR1 gene were also associated with PTSD risk. Gene-environment interaction studies have highlighted the importance of multifactorial vulnerability in PTSD, with epigenetic mechanisms contributing to the equation.