Fibroblast growth factors are structurally related proteins associated with cell 
growth, differentiation, migration, wound healing, angiogenesis, and 
oncogenesis. At the cellular level, their function is mediated by transmembrane 
tyrosinekinase receptors, fibroblast growth factor receptors. Four genes 
encoding fibroblast growth factor receptors have been identified, and mutations 
in three of these, FGFR1, FGFR2, and FGFR3, can cause different congenital, 
autosomal dominant disorders affecting the craniofacial and skeletal 
development: craniosynostosis and chondrodysplasias. The craniosynostosis 
syndromes: Apert syndrome, Beare-Stevenson syndrome, Crouzon syndrome, 
Jackson-Weiss syndrome, Muenke syndrome, Pfeiffer syndrome and Saethre-Chotzen 
syndrome can be caused by mutation in either FGFR1, FGFR2, or FGFR3. 
Saethre-Chotzen syndrome can also be caused by mutation in a functionally 
related gene, ACS. The same mutation can cause different syndromes, and the same 
syndrome can be caused by mutations in different genes. The chondrodysplasias: 
achondroplasia, hypochondroplasia, and thanatophoric dysplasia are all caused by 
mutations in FGFR3.