Male pseudohermaphroditism consistent with 17,20-desmolase deficiency.

A 16-year-old phenotypic female with XY genotype presented an unusual form of nonfamilial male pseudohermaphroditism. Seemingly a normal girl during childhood, the patient failed to undergo pubertal changes presenting with scant pubic hair, absent axillary hair, lack of breast development, retarded bone age and primary amenorrhea. Neither uterus nor adnexa were palpable above the blind-ending vagina. Serum testosterone and estradiol were barely detectable by radioimmunoassay, while LH and FSH reached castrate levels. Two small testes were removed from the pelvic sidewalls which, on biopsy, showed atrophy and hyalinization of seminiferous tubules, but clusters of Leydig cells without signs of hypertrophy or hyperplasia. Administration of testosterone resulted in urinary nitrogen retention and a decrease in serum LH and FSH. Radioimmunoassay of various serum or plasma steroids and gas chromatographic determination of urinary steroids prior to and following ACTH stimulation yielded results which permitted to rule out 20,22-desmolase, 3beta-hydroxysteroid dehydrogenase, 17-hydroxylase and 17beta-hydroxysteroid dehydrogenase deficiency. Low plasma dehydroepiandrosterone sulfate (DHEA-S) and androstenedione (delta4 A) concentrations, low urinary 17-ketosteroid and particularly low dehydroepiandrosterone (DHEA) excretion and the minimal rise of plasma DHEA-S and delta4 A and of urinary DHEA in response to ACTH in conjunction with a normal response of other serum and urinary C-21 steroids are consistent with 17,20-desmolase deficiency. Direct confirmation of this defect, however, seems impossible in the absence of in vitro studies of testicular steroidogenesis.