PLOD1 and cartilage-hair hypoplasia: At the end of puberty, serum LH remained lower in male patients with HH, most markedly in cHH patients (0.64 ± 0.49 IU/l) compared to pHH patients (2.39 IU/l ±1.58) and SLDP patients (3.04 ± 1.54 IU/l, p=0.008).