GNRHR and congenital hypogonadotropic hypogonadism: Genes which are associated with congenital hypogonadotropic hypogonadism include : the Fibroblast Growth Factor receptor 1 gene (FGFR), prokineticin receptor 2 gene (PROKR2), GNRH receptor gene (GNRHR) and the Kallmann syndrome 1(KAL1) sequence gene (also known as ANOS-1) [17].