The endocrine pattern of late onset adrenal hyperplasia (21-hydroxylase deficiency).

We describe 5 adult women with severe hirsutism due to late onset 21-hydroxylase deficiency. Diagnosis was performed on the finding of high serum 17-hydroxyprogesterone (17OHP) levels with a marked hyperresponse to an ACTH test. The endocrine study showed in most patients a gonadotropin behavior similar to that observed in classical polycystic ovary (PCO) syndrome. Prolactin levels were slightly increased in basal conditions and presented an exaggerated response to TRH stimulation.