Finally, deficiencies in IGF-1 and C-RAF have been implicated in some rare and severe human syndromes with defects that include deafness, such as IGF1 deficit (OMIM #147440), Noonan (NS5; OMIM #611553), and Leopard (LPRD2; OMIM #611554) syndromes [7, 29–32]. This evidence concerns the gene IGF1 and deafness.