FGFR2 and Crouzon syndrome: In humans, FGFR mutations have been associated with craniosynostosis in patients with Apert and Crouzon syndromes (FGFR2 gain-of-function mutation) and Muenke syndrome (FGFR3 gain-of-function mutation) (Wilkie et al., 1995; Doherty et al., 2007).