Isolated gonadotropin deficiency in three sisters

Three female siblings with isolated gonadotropin deficiency were studied. None demonstrated hyposmia or craniofacial abnormalities. Single doses of luteinizing hormone-releasing hormone and thyrotropin-releasing hormone (TRH) produced markedly different responses within the kindred. Following administration of TRH, one subject displayed a sharp rise in prolactin, but thyrotropin did not change.