Certain genetic variations among primitive Indian tribal populations were found to be shielding them against malaria, a new study has found.
Malaria claims thousands of lives across the globe annually and is caused by parasite Plasmodium through the bite of an infected mosquito.
While it is known that mutations in genes could lead to genetic diseases, scientists have studied whether genetic variations would lead to either susceptibility to malaria or resistance against the disease.
Initially, samples were collected from patients suffering from the disease from malaria-endemic regions of Chhattisgarh and Odisha as also from normal population in those areas to see if there were any differences among them at genetic level.
Although genetic variations in Interleukin-4 (IL-4), an anti-inflammatory gene have been reported to affect the risk of infectious and auto-immune diseases, this was the first study to look into its contribution in malaria, according to Kumaraswamy Thangaraj, senior author of the study and Deputy Director, the Centre for Cellular and Molecular Biology.
Beside the CCMB, nine other research and academic institutions from India and abroad, including Germany, Vietnam, Syria and Brazil were involved in the study, which was published online in PLOS One journal.
Variations in IL-4
In this study, 4,216 individuals, a majority from India and the rest from Brazil, Vietnam and Syria were investigated for three specific variations in IL-4. The study subjects from India included different tribes, castes and linguistic groups. The variation, which gave resistance against malaria was found to be in the primitive Indian tribal population as compared to other caste and tribal groups.
Dr. Thangaraj said since primitive tribal population were living in remote places without the aid of modern facilities against mosquito bite, they have been exposed to various parasites over hundreds of years.
This exposure over a long period must have automatically led to some mechanism to protect against malaria through the process of natural selection.
He said the findings would help in screening populations for susceptibility and resistance to malaria.