Isolated hypogonadotropic hypogonadism, also called idiopathic or congenital hypogonadotropic hypogonadism, as well as isolated or congenital gonadotropin-releasing hormone deficiency, is a condition which results in a small subset of cases of hypogonadotropic hypogonadism due to deficiency in or insensitivity to gonadotropin-releasing hormone where the function and anatomy of the anterior pituitary is otherwise normal and secondary causes of HH are not present. Wikipedia