Patients were observed in five Italian tertiary centers of Pediatric Endocrinology, in the periods March–September 2020 and March–September 2019. CPP was defined when a detectable basal LH level (>0.2 IU/L) and/or a peak response of LH after GnRH infusion >5 IU/L, and/or serum estradiol levels >20 pg/mL. Here, PLOD1 is linked to central precocious puberty.