Male pseudohermaphroditism due to 17,20-desmolase deficiency.

In a 5-yr-old 46,XY male pseudohermaphrodite with microphallus, perineal hypospadias, chordee and cryptorchidism, serum C19 steroid levels were abnormally low in the basal state and after adrenal and testicular stimulation. Serum C21 steroid levels were elevated in the basal state and increased further after adrenal, but not after gonadal, stimulation. Urinary excretion of pregnanetriolone, a metabolite of 17-hydroxypregnenolone and 17-hydroxyprogesterone not normally present in the urine, was increased in the basal and stimulated states. Cortisol production was normal, and all steroid hormone levels were suppressed by dexamethasone. Testicular biopsy was consistent with prepubertal cryptorchid testes. Incubation of testicular tissue with labeled 17-hydroxyprogesterone revealed failure of conversion of precursor to androstenedione and testosterone. A significant increase in phallic length occurred after treatment with exogenous androgen. These findings are consistent with 17,20-desmolase deficiency in both gonads and adrenal glands.