It is known that gain of function (GOF) mutations in FGFR2, primarily in the III Ig-like domain and the adjacent linker regions (exons IIIa and IIIc), can cause several different types of autosomal dominant craniosynostosis, including Crouzon syndrome, Pfeiffer syndrome, and Apert syndrome [17]. Here, FGFR2 is linked to Crouzon disease.