Carbohydrate-deficient glycoprotein syndrome in a girl with hypogonadism due to inactive follicle stimulating hormone.

We report a very rare case of a girl with hypogonadism probably due to inactive FSH. She had been diagnosed as carbohydrate-deficient glycoprotein syndrome. The 14-year-old patient had no secondary sexual characteristics with the 46,XX karyotype and estradiol (E2) levels were undetectable. Follicle stimulating hormone (FSH) levels were extremely high and responded exaggeratedly to luteinizing hormone-releasing hormone (LH-RH). The E2 levels, on the other hand, were elevated after stimulation with human menopausal gonadotropin (75 units/day) for 5 days, suggesting biologically inactive FSH in the circulation. Abnormal structure in the glycoprotein may be possibly related with hypogonadism.