What is the main reason for this disease? A: Idiopathic hypogonadotropic hypogonadism (IHH) is a relatively common congenital genetic disorder that is caused by defects in the synthesis, secretion or action of gonadotropin-releasing hormone (GnRH) hormone or abnormal migration of GnRH neurons resulting in insufficient secretion of pituitary gonadotropins, namely luteinizing hormone (LH) and follicle-stimulating hormone (FSH), followed by pubertal development The disease is characterized by a partial or complete absence of pubertal development.