FKBP5 polymorphisms are linked to inherited sensitization or reactivity of the HPA axis, lowering the threshold for trauma or fear.

“And the FKBP5 polymorphisms maps to a location in the genome that's associated with the so-called glucocorticoid system with cortisol release. So the predisposition that one might inherit from having a parent father or mother but stronger tendency to inherit it from the father. Who experienced abuse is one in which the glucocorticoid system, the cortisol system, and that HPA axis that we talked about before the hypothalamic-pituitary-adrenal axis is sensitized or reactive in a way that sets a lower threshold to become traumatized or very afraid of certain types of events.”