Table 3. Etiology of precocious puberty. CNS: central nervous system, CAH: congenital adrenal hyperplasia.

Type
Gonadotrophin Dependent	Idiopathic Brain abnormality: hypothalamic hamartoma, hydrocephalus, arachnoid cysts, septo-optic dysplasia CNS damage: trauma, infiltration, infection, irradiation Tumors CNS Genetic mutation: Activation of the KISS1/KISS1R pathway, inactivating mutations of MKRN3 and DLK1.
Gonadotrophin Independent	CAH McCune-Albright Syndrome Tumor (ovary, testis, adrenal) Testotoxicosis (LH receptor mutation) Human chorionic gonadotropin (hCG) secreting germ cell tumors Primary hypothyroidism Exogenous sex steroids