September 23, 2009

Genome-scale Asian Indian study completed

U.S. and Indian scientists say they have conducted the first genome-scale analysis of the relationship of the ancestral populations of India to modern groups.

The international team was led by Associate Professor David Reich of the Broad Institute of Harvard University and the Massachusetts Institute of Technology, in collaboration with Lalji Singh, former director of the Center for Cellular and Molecular Biology in Hyderabad, India.

The researchers said they analyzed more than 500,000 genetic markers across the genomes of 132 individuals from 25 diverse groups, representing 13 states, all six language families, traditionally upper and lower castes and tribal groups.

The team found strong evidence for two distinct ancestral groups in the genes of modern people in India. One group, called Ancestral North Indians, is genetically similar to western Eurasians, while the other group, Ancestral South Indians, possesses a distinct genetic pattern not found anywhere else in the world.

The scientists said their findings have medical implications since the genetically distinct subgroups have many different underlying genetic risks that can now be identified and studied to help in clinical care of individuals and their families.

This work is an outstanding example of the power of international collaboration, said Singh. Scientists in India and the United States have together made discoveries that would have been impossible for either group working alone.

The research is reported in the journal Nature.