Precocious puberty has been classically defined as the onset of secondary sexual characteristics in girls younger than 8 years old and in boys younger than 9 and a half years old. Central precocious puberty (CEPREPU) refers to a gonadotropin-dependent type which results from premature activation of the hypothalamic-pituitary-gonadal axis (HPG). CEPREPU is much more frequent in girls than in boys (up to 20:1 ratio). Recently, kisspeptin receptor (KISS1R) and its ligand, kisspeptin, were revealed as major gatekeepers of puberty onset. Mutations of the KISS1R gene were described in patients with impaired pubertal development. On the other hand, it has been reported that heterozygous mutations of the LHCGR gene cause gonadotropin-independent precocious puberty in males, but have no detectable effects on prepubertal or postpubertal females.
