Abstract: Since population genetic STRUCTURE can increase false-positive rate in genome-wide association studies (GWAS) for complex diseases, the effect of population stratification should be taken into account in GWAS. However, the effect of randomly selected SNPs in population stratification analysis is underdetermined. In this study, based on the genotype data generated on Genome-Wide Human SNP Array 6.0 from unrelated individuals of HapMap Phase2, we randomly selected SNPs that were evenly distributed across the whole-genome, and acquired Ancestry Informative Markers (AIMs) by the method of f value and allelic Fisher exact test. F-statistics and STRUCTURE analysis based on the select different sets of SNPs were used to evaluate the effect of distinguishing the populations from HapMap Phase3. We found that randomly selected SNPs that were evenly distributed across the whole-genome were able to be used to identify the population structure. This study further indicated that more than 3 000 randomly selected SNPs that were evenly distributed across the whole-genome were substituted for AIMs in population stratification analysis, when there were no available AIMs for spe-cific populations.

Key words: genome-wide association study, population stratification, ancestry informative markers, random SNP, Af-fymetrix SNP 6.0 array