PLXNA3 and congenital adrenal hyperplasia: On the other hand, when the source is endogenous, like in congenital adrenal hyperplasia (CAH), elevated level of adrenocorticotrophic hormone (ACTH) increases the adrenal’s sex hormone (androstenedione) production, resulting in negative feedback on pituitary and hypothalamus, thus suppressing testicular androgens production.