Scientists have discovered a gene that is responsible for an inherited form of cleft lip and palate. A pair of twins born in Brazil were found to be genetically identical, but a doctor noticed that one of them had been born with a cleft palate, while the other had not.
The twin with the cleft palate has Van der Woude syndrome (VWS), a condition which, because of its pattern of inheritance, was already thought to be caused by a mutation on a single gene. But the gene responsible had not yet been identified.
The scientists realised that the gene mutation that caused the VWS in one of the twins must have happened after the embryo naturally split in two. Scientists had been looking for the genetic link to VWS for many years. Now, those involved in the search, a collaboration from the Manchester University in the UK and the University of Iowa in the US, have identified the gene as IRF6. They were able to find the mutation by simply comparing the genetic make-up of the twins, using data collected from the Human Genome Project.