Genetic Landscape of The People of India: An Indian Genome Variation Consortium Effort Spearheaded by CSIR (2003-2007)

The largest scientific endeavor in the field of biology (after the green revolution effort of ICAR in the 1970s), involving over 150 scientists and researchers drawn from six CSIR laboratories (IGIB, IICB, CCMB, CDRI, ITRC, IMT), Indian Statistical Institute, Kolkata and anthropologists from various institutes of India, and The Centre for Genomic Applications, Delhi, has generated genetic information on over 4000 genetic markers from over 1000 biomedically important and pharmacogenetically relevant genes in reference populations encompassing diversity of populations from across the country. The first phase of these results on 55 populations involving several hundred markers has been released in the April 2008 issue of Journal of Genetics (J Genet, 87, 3-20, April 2008). Revealing this at a press conference in New Delhi today, Union Minister for Science & Technology and Earth Sciences, Shri Kapil Sibal said that it would help in the construction of ‘specific drug response/disease predisposition maps’ to aid policy level decision making for drug dosage interventions and disease risk management, especially for complex as well as infectious diseases.

Interacting with the media, DG, CSIR and the leader of this endeavour Prof. Samir K. Brahmachari said that this monumental study has resulted in a clear genetic profile of our populations, explicitly indicating that there is a strong association between genetic and linguistic profiles in India and that there are significant genetic differences in the frequencies of disease-associated genetic markers. For example, this study has revealed that a known protective genetic marker against HIV-1 is virtually absent in India, implying the absence of natural or genetic protection against HIV-AIDS in our country.

The overall results of this study would help in (a) making predictions of both diseases as also the effectiveness of specific drugs used for various diseases, and (b) designing future scientific studies to understand genetic underpinnings of major diseases in India. These results have also provided the first set of insights into the processes of human adaptation to different types of environment in India.

Earlier, in 2002, The International HapMap Consortium initiated a program to build the next generation map of human genome at the total cost of US$ 100 million. To capture the extent of genomic diversity, the above study covered 45 Chinese, 45 Japanese, 90 Caucasian, and 90 African individuals. Fully realizing that 45 samples cannot represent total diversity of India, the Indian Genome Variation Consortia was launched independently to study a large number of samples (over 2000 samples drawn from 55 populations) on smaller number of highly informative markers, cost-effectively (at 1/20th cost of the HapMap Consortium). In addition, 58,000 SNPs (50K Affymetrix array) were analyzed in about 600 individuals representing 26 populations from four major clusters, as a part of this study.

The study reveals that the genetic landscape of Indian populations captures the genetic diversity of the world - Indian populations form a continuum of genetic spectrum bridging the two distinct HapMap populations, the Caucasians and the Oriental Asians. Besides, there are populations that are unique to India mostly derived from Austro-Asiatic and Dravidian speaking populations. These findings have major implications in designing drug-discovery studies and selecting suitable populations for testing drug efficacy. For instance, a pilot pharmacogenomic study on response to salbutamol (a Beta-2-adrenergic agonist used to treat asthma) identified genetic markers in a receptor gene which could classify individuals as poor and good responders – a finding that would help in better management of the disease.

A large number of projects have been undertaken in the XIth Plan that are aimed at utilizing this basal data for predictive marker discovery and pharmacogenomics. Additional data are available in The Indian Genome Variation database (http://igvdb.res.in). The paper consisting the study is available at www.ias.ac.in/jgenet/Forthcoming.html

Source: Press Information Bureau
Date: April 25, 2008