Testicular response to exogenous gonadotropins in the syndrome of feminizing testes.

The steroid response of testes to exogenous gonadotropin administration was studied before castration in a patient with the complete form of the testicular feminization syndrome. Urinary steroid determination were made along with measurements of plasma testosterone during adrenal suppression with dexamethasone and after stimulation with human menopausal gonadotropin (HMG) and HMG plus human chorionic gonadotropin (HCG). Our data provide evidence that the gonads in the testicular feminization syndrome synthesize steroids normally. Estrogens and testosterone are secreted by the testes, and the Leydig cells of the testes are capable of responding to exogenous HMG and HCG stimulation. These findins are consistent with the hypothesis that there is no abnormal testicular steroidogenesis in these genotypic males. Additional evidence is provided that these gonads secrete testosterone in amounts comparable to those of normally functioning testes. Failure of virilization in the presence of androgen secretion as indicated by previous authors is probably the result of a deficiency of androgenic action at the end organs. The presence of sparse pubic and axillary hair in the mother and the finding of the same type of karyotype (46,XY) in a sibling suggest that hereditary factors play a role in this disorder.