Investigation of common disease-associated polymorphisms within Asian Indians. T.J. Pemberton, N. Mehta, H. Allayee, P.I. Patel. Institute for Genetic Medicine, University of Southern California, Los Angeles, CA.
   Asian Indians display a high prevalence of diseases linked to changes in diet and environment that have arisen as their lifestyle has become more westernized. In the case of coronary artery disease, Asian Indians exhibit unique characteristics that distinguish them from the other populations, suggesting that unique causative factors underlie this and possibly other related diseases. Recent STRUCTURE analysis using 1200 genome-wide polymorphisms in 432 individuals from 15 Asian Indian language groups has shown that: (i) Indians constitute a distinct cluster, and (ii) despite the geographic and linguistic diversity of the groups they exhibit a low level of genetic differentiation. We have now investigated the prevalence of disease-associated polymorphisms that have recently been reported to be risk factors for atherosclerosis, hypertension, diabetes, prostate cancer, Hirschsprung disease, and age-related macular degeneration within 576 individuals from the same Indian groups. All of these diseases have a high prevalence in Asian Indians. Analysis of the data revealed no allele frequency differences between the different language groups. We did however find allele frequency differences between this Asian Indian cohort and previously reported populations for certain polymorphisms. Most striking was the high abundance of the DG8S737 allele associated with an increased risk of prostate cancer (24.5%) but only a relatively moderate abundance of the disease-associated allele of the SNP, rs1447295 (12.9%). These two polymorphisms were found to be in high linkage disequilibrium (LD) within the other populations; however our data suggests that they are not in LD within the Asian Indian population. Further studies in Asian Indian disease cohorts will be needed to confirm an association between DG8S737 and the SNP rs1447295 with prostate cancer in Asian Indians.