Mutations in the KISS1 gene or KISS1R can lead to idiopathic hypogonadotropic hypogonadism and delay pubertal maturation of the gonadotropic axis, suggesting that KISS1R is indispensable for normal GnRH secretion [10, 11, 13, 14, 21–25]. This evidence concerns the gene KISS1 and hypogonadotropic hypogonadism.