Hypogonadism in Prader-Willi syndrome.

Sexual development was evaluated in 9 female and 2 male subjects with Prader-Willi syndrome. The process of sexual development and degree of genital development attained were found to be variable but abnormal in all subjects. Hypothalamic-pituitary-gonadal functions were evaluated by measurement of serum Luteinizing Hormone and plasma testosterone responses to stimulation by clomiphene citrate and plasma testosterone responses to stimulation by human chorionic gonadotrophin. The degree of vaginal estrogenization was variable. The testicular biopsies showed abnormalities mainly in the germinal epithelium. In agreement with previous studies, it was concluded that the abnormalities of sexual development in this syndrome are mainly due to a defect in the hypothalamic pituitary axis. Adrenal function was not found to be grossly abnormal. The 17 ketosteroid excretion values were low, probably explaining the rather sparse pubic and axillary hair observed in these patients. The urinary 17-hydroxycorticosteroid creatinine ratios were found to be elevated, probably due to decreased creatinine excretion, reflecting the muscular abnormalities of these subjects.