Researchers have found that flaw in a gene linked to birth defects in mouse models may cause cleft lip and palate in humans too.

In the study, three siblings born with cleft lip and palate were found to have the same gene mutation associated with the birth defect. The gene intraflagellar transport 88 (IFT88) ensures transportation antennae (cilia) on embryonic cells travel to the right place, enabling the development of cartilage, bone and smooth muscle in the face and skull.

"Finding this birth defect in every single child in a family is like catching lightning in a bottle because it allowed us to pinpoint the gene mutation that is probably responsible," said senior author of the study Yang Chai from University of Southern California in the US. "Our finding that the gene IFT88 is involved in cleft lip and palate is unlikely to be mere coincidence," Chai said.

However, because this study - published in the journal Human Molecular Genetics -- involved only three children, Chai said more investigation is needed to find a causal relationship. Operation Smile, an international nonprofit that provides free facial surgeries in developing countries, found and provided support to the three siblings -- two boys and a girl -- in Mexico who were born with cleft lip and palate.  Their mother did not have the congenital disorder, but their father did. Researchers went through 32,061 unique gene variations to identify IFT88.

"If someone carries this mutation, they may have a higher chance of giving birth to children with cleft lip and palate," said Chai. "In our study, the animal model and the human mutation match," Chai said.  "In the animal model, there is no doubt. We have shown that 100 per cent of the mice who have a single mutation in IFT88 have cleft lip and palate," Chai added.