Novel and de novo mutations of the IRF6 gene detected in patients with Van der Woude or popliteal pterygium syndrome

The interferon regulatory factor 6 gene (IRF6) has been identified as the major Van der Woude (VWS) syndrome and popliteal pterygium (PPS) syndrome gene with mutations in the majority of the kindreds. We have studied altogether 17 kindreds from Sweden, Finland, Norway, Thailand and Singapore, and report here 10 mutations, six of them previously unseen. In two kindreds, we could document de novo mutations, both of them changing a codon for a glutamine residue to a stop. No mutation could be detected in the four VWS kindreds from Finland, suggesting a founder effect for a mutation in an atypical noncoding position. Our findings demonstrate that several distinct mutations occur in the Swedish population, and confirm the general notion of a broad spectrum of IRF6 mutations underlying the VWS/PPS phenotypes.