FKBP5 and post-traumatic stress disorder: Interestingly, increased methylation of SNPs in the FKBP5 gene (e.g., rs9296158) and some CRHR1 gene polymorphisms that produce high levels of CRH are associated with cortisol hypersensitivity and hypercortisolism and represent a distinct PTSD phenotype from that characterized by hypercortisolism [156].