Genetic database may change medicine for Indians

The world's first genetic database exclusively for the Asian population has yielded surprises for Indians and will be a critical tool to develop drugs and diagnostic more suited for the Indians in the future.

In addition, the GenomeAsia100K Project may also shed new light on the ancestry of Indian as well as Asian people.

Half-a-dozen Indian institutions including a Bengaluru-based outfit made key contributions in realising the Asian genetic data bank.

Since the existing global genetic data-sets have less than 10% contribution from Asia, studies based on such data have somewhat reduced significance for the Indian population.

For instance, 30-40% of the data generated by the currently available DNA microarrays do not provide useful information on Indian populations.

“We have discovered about 200,000 previously unreported novel DNA variants among Asians. Alterations of proteins are usually associated with disease and 23% of protein-altering variants found in Asia are unreported in existing databases,” said Partha Pratim Majumder, a distinguished scientist at the National Institute of Biomedical Genomics, Kalyani and a key member of the consortium.

“These novel data are critical to the discovery of genes pertaining to diseases that are of high prevalence in Asia and to the design of better DNA microarrays for use in Asia.”

To bridge the Asian genetic data gap, the genome Asia consortium was set up in 2016 involving academic institutions and the biotechnology industry. One of the industry partners, MedGenome, is based in Bengaluru.

The consortium members analysed of whole-genome sequences of 1,739 individuals from 219 populations spread across most countries of Asia, of whom 598 are from Indian tribal and non-tribal groups.

“We discovered that even some large urban populations of India (the population of Chennai) exhibit genetic characteristics that are usually found in isolated populations and there are novel DNA variants even in many well-studied genes implicated in diabetes, thalassemia, and breast cancer,” Majumder said.

The study showed that carbamazepine, a drug used for the treatment of some mental disorders, might have adverse effects on about 400 million speakers of Austronesian languages resident in southeast Asia. Several other drugs too have adverse effects on individuals who possess some specific DNA variants.

Published in Nature on Wednesday, the research paper also provided new evidence of mating of an archaic and extinct human species called Denisovans with modern humans. Such mixing has left generic imprints across Asia, including in Indian populations.

“We have found that five predominant ancestral admixture events seem to have taken place to give rise to the present-day Indian populations, including the populations of Andaman and Nicobar islands,” he said. For the Asian population, as many as 14 such admixtures took place.