- Apert syndrome results from localized mutations of FGFR2 and is allelic with Crouzon syndrome. Wilkie, A.O., Slaney, S.F., Oldridge, M., Poole, M.D., Ashworth, G.J., Hockley, A.D., Hayward, R.D., David, D.J., Pulleyn, L.J., Rutland, P. Nat. Genet. (1995)