- Hay-Wells syndrome is caused by heterozygous missense mutations in the SAM domain of p63. McGrath, J.A., Duijf, P.H., Doetsch, V., Irvine, A.D., de Waal , R., Vanmolkot, K.R., Wessagowit, V., Kelly, A., Atherton, D.J., Griffiths, W.A., Orlow, S.J., van Haeringen, A., Ausems, M.G., Yang, A., McKeon, F., Bamshad, M.A., Brunner, H.G., Hamel, B.C., van Bokhoven, H. Hum. Mol. Genet. (2001)