Autosomal dominant form of Kallmann syndrome (KAL2) (OMIM 147950), which is characterized by hypogonadism and anosmia, and also clefting in 5-10% of the cases is caused by mutation in the gene encoding fibroblast growth factor receptor-1.[67] FGFR1 (fibroblast growth factor receptor-1), encodes a transmembrane receptor tyrosine kinase that transduces signals from secreted FGFs.[68] Dode et al.[69] confirmed that loss-of-function mutations in FGFR1 account for approximately 20% of all cases of Kallmann syndrome. Here, FGFR1 is linked to hypogonadism.