Although a specific heterozygous mutation of MSX2 encoding Pro148His was the first molecular lesion to be described in craniosynostosis in 1993,49 only two further families (both segregating p.Pro148Leu) have subsequently been reported worldwide,33, 34 and the family described here (also with p.Pro148Leu) is the first known in the UK. The gene discussed is MSX2; the disease is craniosynostosis.