Around 2,650 babies are born with a cleft palate each year in the US. Now, a revolutionary new study indicates it might one day be possible to reverse this common birth defect while still in the womb. So far, the research has only been carried out in mice, but the team are optimistic that their work could be applied to humans too.

The study, published in the journal Development, actually set out to look at tooth development. They confirmed that two sets of genes, known as PAX9 and Wnt genes, play a role in regulating tooth formation. They also found that these genes code for the palatal shelves of the mouth to grow and fuse in the midline.

"It was really serendipitous," explained lead researcher Rena D'Souza, professor of dentistry at the University of Utah Health, in a statement. "For the first time, we can show the involvement of the Wnt pathway during palate fusion."

A cleft palate forms if the tissue that makes up the roof of the mouth does not fuse together completely between the sixth and ninth weeks of pregnancy. It results in a gape in the roof of their mouth that requires reconstructive surgery and fiddly life-long treatments.

"As a clinician, I understand the devastating consequences of cleft palate," professor D'Souza added.

Now, scientists know this happens because mice, and people, lack the gene PAX9. The mice missing the PAX9 gene also had an increase in two genes, called Dkk1 and Dkk2, that block the Wnt signaling pathway.

Armed with this knowledge, D'Souza and her team gave pregnant mice with the PAX9 gene a drug that inhibited Dkk, thereby unblocking the Wnt signaling pathway. The baby mice were born with totally normal palates and experienced no adverse health effects.

This is all very well for mice, but could humans benefit from this discovery? The researchers are optimistic that the treatment could be translated to humans, although they need to carry out far more work to see if it really is as safe and effective as it appears to be in mice.

"Clearly, there is more work to be done prior to implementation for humans, but it seems feasible to translate this research into Wnt-based treatments for people," concluded D'Souza.