On the contrary, low or inappropriately normal LH and FSH levels in the context of low sex-steroid levels (hypogonadotrophic hypogonadism) typically indicates hypothalamic-pituitary pathology e.g. FHA in menstrual disturbances and in delayed puberty suggests persistent (CHH), or spontaneously-resolving (CDGP) pubertal delay [18]. Here, PLOD1 is linked to cartilage-hair hypoplasia.