For patients with LTL, if both LH and FSH levels were elevated, they could be classified as having primary hypogonadism; for those with unelevated LH and FSH levels, they could be classified as having secondary hypogonadism, which is closely associated with obesity and the hypothalamus-pituitary axis (41). Here, PLOD1 is linked to obesity due to melanocortin 4 receptor deficiency.