Mini-Review J Mol Genet Med (December 2005), 1(2), 43-48 doi: jmgm Published online: 30 December 2005 Full Text: (html | pdf ~261kb | refs) Population stratification and genetic association studies in South Asia Alan H Bittles Centre for Human Genetics, Edith Cowan University, 100 Joondalup Drive, Perth WA 6027, Australia Correspondence to: Alan H Bittles, Email:a.bittles@ecu.edu.au, Tel: +61 8 63045623, Fax: +61 8 63045851 Received: 25 November 2005, Accepted: 13 December 2005 © Copyright The Author ----------------------------------------------------------------------------------------------------------------- ABSTRACT Population stratification and its influence on genetic association studies is a controversial topic. Although it has been suggested that stratification is unlikely to bias the results of association studies conducted in developed countries, convincing contrary empirical evidence has been published. However, it is in populations where historical ethnic, religious and language barriers exist, that community subdivisions will predictably exert greatest genetic effect, and influence the organization of association studies. In many of the populations of the Indian sub-continent, these basic population divisions are compounded by a strict tradition of intra-community marriage and by marriage between close biological relatives. Data on the very significant levels of genetic diversity that characterize the populations of India and Pakistan, with some 50,000-60,000 caste and non-caste communities in India, and average first cousin marriage rates of 40%-50% in Pakistan, are presented and discussed. Under these circumstances, failure to explicitly control for caste/biraderi membership and the presence of consanguinity could seriously jeopardize, and may totally invalidate, the results of association/case control studies and clinical trials. KEYWORDS: Stratification, endogamy, consanguinity, association studies, India, Pakistan ----------------------------------------------------------------------------------------------------------------- Privacy | Disclaimer |