Although variants of FGFR1 gene have been postulated to be classically associated with Kallmann syndrome and Normosmic Idiopathic Hypogonadotropic Hypogonadism, more recent studies advocate that they might be also involved in the formation of the midline brain structures such as the pituitary, optic region, and septum pellucidum causing a wider phenotype of CPHD and SOD. This evidence concerns the gene FGFR1 and hypogonadotropic hypogonadism.