We recently found [71] that in both an exploratory sample (n = 126) and in the whole validation sample (n = 50) of men consulting for sexual dysfunction with secondary hypogonadism, total T ≤ 6.1 nmol/L or LH ≤ 1.9 U/L should raise the suspicion of hypothalamus/pituitary structural abnormalities, warranting an MRI evaluation (odd ratio for pituitary abnormalities = 5.49 [1.32;22.85], and 3.31 [1.02;10.72] for total T and LH, respectively). Here, PLOD1 is linked to hypogonadotropic hypogonadism.