An algorithm for the differential diagnosis of HH and CDP by using S has been developed.CONCLUSION: The result of scoring of LH, FSH, testosterone, inhibin B levels ≥55.07 makes it possible to diagnose hypogonadotropic hypogonadism, < 21.16 — constitutional delay of puberty with a high probability. The gene discussed is PLOD1; the disease is hypogonadotropic hypogonadism.