2. To diagnose central gonadal deficiency, patients will be asked if they had amenorrhea or oligomenorrhea prior to estrogen replacement. An FAH of less than 5 MIU/ML will be used to confirm that they have central and not primary gonadal deficiency. In select patients in which the diagnosis of central gonadal deficiency is unclear, we may perform an LHRH stimulation test, in which 100 ug iv of LHRH (Factrel) will be given and a peak LH response of less than 15 MIU/ML will be considered consistent with central gonadotropin insufficiency.