At the time of CPP diagnosis, patients in PP group had an increase of 2.0 ± 1.6 years in bone age, and LH and FSH levels were 0.3 ± 0.7 (mIU/ml) and 2.4 ± 1.4 (mIU/ml), respectively. Here, PLOD1 is linked to central precocious puberty.