CHENNAI: A city-based research team has found a rare genetic mutation which, they believe, could be at the root of infants born with cleft lip and palate among the ‘Dravidian Tamil’ population. In a paper published in the European Journal of Dentistry, geneticist and orthodontist duo — Dr Arvind Ramanathan and Dr Deepak Chandrasekhar — explains how they had this sort of a DNA analysis on patients with cleft lip and cleft palate (CLP) that had not been attempted before for specific population types in India.
A need to understand why children were born with deformed lips and unshapely palates in India, was at the base of their study. “Genetic studies have been conducted among Caucasians and other leading races in the West to identify genetic defects that are present in patients born with CLP, but nothing had been attempted here before this,” said Dr Arvind. Earlier this year, the team, which works out of a genetic lab at the Sree Balaji Medical and Dental College and Hospital, began reaching out to orthodontists and maxillofacilary surgeons across the State for blood samples from their target population, spread across Tamil Nadu.
“Doctors from Salem, Coimbatore, Namakkal and many other places sent us samples of blood from their CLP patients and we finally had 60 samples to work with,” he added.
Interspersed with 60 samples from normal children, they began studying the direct DNA structures in their lab. “The focus was on a gene called ARHGAP29 to find if there was a mutation related to it, because this gene’s functioning is essential to fusion of a normal lip and palate,” he explained. Eventually, it paid off. “In one of the 60 samples, we had a breakthrough. We found that there was a mutated strain that stopped short of making a specific protein. This strain was present along with the normal strain, indicating that it could well be an intrinsic cause for this condition with respect to our Tamil populace.”
Cleft lips and palates are known to occur in one in 800-1,000 births in the country. An insight into which genetic mutation causes this condition could in ‘5-10 years’ create the possibility of gene therapy to correct it before the child is formed itself. “We need to do some live testing with mice in the next stage, but that is the eventual aim. More samples for a larger study need to be done before we look at gene modification therapy,” he concluded.