Apert syndrome is an autosomal dominant disease characterized by craniosynostosis and bony syndactyly associated with point mutations (S252W and P253R) in the fibroblast growth factor receptor (FGFR) 2 that cause FGFR2 activation.
The craniofacial appearance following craniofacial surgery was better in patients with the P253R mutation, whereas these patients showed a more pronounced severity of the syndactyly.
Apert syndrome, characterized in addition by syndactyly of the limbs, involves specific mutations at two adjacent residues, Ser252Trp and Pro253Arg, predicted to lie in the linker region between IgII and IgIII of the FGFR2 ligand-binding domain.
Since these two alterations have been observed exclusively among these patients, it has been suggested that the S252W and P253R changes may play an important role in the occurrence of syndactyly.