PLOD1 and central precocious puberty: Patients who were diagnosed with CPP and started GnRH analog therapy between April 1 to July 1, 2019 (Group 1), and April 1 to July 1, 2020 (Group 2). Precocious puberty diagnostic criteria are that breast development starts before the age of 8 in girls, basal LH value is above 0.3 IU/L, and GnRH stimulation test LH peak was over 5 IU/L.