PLOD1 and hypogonadotropic hypogonadism: His biochemical investigations showed frank hypogonadotropic hypogonadism (serum testosterone: 67 ng/dL; LH: 2.18 mIU/ml and FSH: 3.89 mIU/ml) with neuroendocrine studies revealing low-amplitude low-frequency LH pulse profile consistent with hypogonadotropism (Fig. 9).