title: Low levels of genetic divergence across geographically and linguistically diverse populations from India.
abstract: Ongoing modernization in India has elevated the prevalence of many complex genetic diseases associated with a western lifestyle and diet to near-epidemic proportions. However, although India comprises more than one sixth of the world's human population, it has largely been omitted from genomic surveys that provide the backdrop for association studies of genetic disease. Here, by genotyping India-born individuals sampled in the United States, we carry out an extensive study of Indian genetic variation. We analyze 1,200 genome-wide polymorphisms in 432 individuals from 15 Indian populations. We find that populations from India, and populations from South Asia more generally, constitute one of the major human subgroups with increased similarity of genetic ancestry. However, only a relatively small amount of genetic differentiation exists among the Indian populations. Although caution is warranted due to the fact that United States-sampled Indian populations do not represent a random sample from India, these results suggest that the frequencies of many genetic variants are distinctive in India compared to other parts of the world and that the effects of population heterogeneity on the production of false positives in association studies may be smaller in Indians (and particularly in Indian-Americans) than might be expected for such a geographically and linguistically diverse subset of the human population.
authors.affiliation: Department of Human Genetics, Bioinformatics Program, and the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America. rnoah@umich.edu
authors.forename: Noah A
authors.initials: NA
authors.lastname: Rosenberg
authors.forename: Saurabh
authors.initials: S
authors.lastname: Mahajan
authors.forename: Catalina
authors.initials: C
authors.lastname: Gonzalez-Quevedo
authors.forename: Michael G B
authors.initials: MG
authors.lastname: Blum
authors.forename: Laura
authors.initials: L
authors.lastname: Nino-Rosales
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Ninis
authors.forename: Parimal
authors.initials: P
authors.lastname: Das
authors.forename: Madhuri
authors.initials: M
authors.lastname: Hegde
authors.forename: Laura
authors.initials: L
authors.lastname: Molinari
authors.forename: Gladys
authors.initials: G
authors.lastname: Zapata
authors.forename: James L
authors.initials: JL
authors.lastname: Weber
authors.forename: John W
authors.initials: JW
authors.lastname: Belmont
authors.forename: Pragna I
authors.initials: PI
authors.lastname: Patel
mesh_terms: D000483:Alleles; D016000:Cluster Analysis; D004251:DNA Transposable Elements / Q000235:genetics; D005060:Europe; D005202:Asia, Eastern; D017353:Gene Deletion; D005787:Gene Frequency; D014644:Genetic Variation; D006801:Humans; D007194:India / Q000208:ethnology; D007802:Language; D018895:Microsatellite Repeats / Q000235:genetics; D008877:Middle East; D011110:Polymorphism, Genetic; D012984:Software
chemical_list: D004251:DNA Transposable Elements