Girls with CPP were divided into two groups: Group 1 (Post-lockdown Group) including patients whose first signs of CPP appeared as of the beginning of lockdown in March 2020 until July 2021; Group 2 (Pre-lockdown Group) comprising patients whose first signs of CPP appeared between 2014 and February 2020. CPP is defined as thelarche before the age of 8 for females, LH levels of 5 mU/L or greater (either basal or after stimulation with GnRH) detected within the age of 9. The gene discussed is GNRH1; the disease is central precocious puberty.