Gene behind milk indigestion
doi:10.1038/nindia.2011.137 Published online 26 September 2011
Researchers have identified the genetic variation that predisposes Indian children to lactose intolerance after weaning. This insight may help design a genetic screening test to diagnose the risk of lactose intolerance among Indian children.
Lactose intolerance is the inability to digest lactose in milk and dairy products. It occurs when the small intestine doesn't make enough lactase enzyme — a condition known as adult-type hypolactasia. High activity of lactase enzyme has been linked to the C/T-13910 variant of the lactase gene.
Studies have tried to link the deficiency of this gene variant to adult-type hypolactasia. However, such genetic links among Indian children were unexplored. Researchers have now established this link by studying the intestinal biopsy specimens of 176 Indian children aged between 1 and 16.
A total of 56.8% children carried the gene variant C/C-13910 associated with the onset of adult-type hypolactasia. Among them, 40.9% also carried the gene variant C/T-13910, linked to high lactase activity. Children below five exhibited high lactase activity for both gene variants. Children between 5-16 with the C/C-13910 gene variant showed very low lactase activity and those with the C/T-13910 gene variant showed high activity.
The results indicate the possibility of early genetic screening for detecting the onset of adult-type hypolactasia in Indian children.