Researchers at the University of Helsinki have described a new, recessively inherited human syndrome featuring craniosynostosis, maxillary hyperplasia, delayed tooth eruption and extra teeth.1

In craniosynostosis, the sutures between skull bones become ossified prematurely, affecting skull shape and limiting space for the growth of the brain. It is observed in 1:25,000 births and often requires operative surgery. Supernumerary teeth are more common, and in most cases they also require dental surgery.

A combination of these anomalies was observed in four children of a Pakistani family living in Denmark. Extra teeth developed in positions suggesting that they may represent a third set of teeth.

The parents of the family were first cousins, which made it possible to localise the gene in the genome and identify the mutation, causing a change of a single amino acid, in a gene for interleukin 11 receptor alpha (IL11RA). This is a protein on cell surface that binds the extracellular interleukin 11 and makes possible for the cells to sense the presence of this factor.

'In the future it may be possible to use modulation of IL11 signaling for treatment of craniosynostosis,' said Dr Pekka Nieminen, the leader of the study.