LD relationships between SNPs may differ between ethnic groups so we have deposited, as a central resource of our web server, the information on SNP genotype data and pairwise LD for each ethnic group. This allows the user to incorporate the results of a GWAS from one ethnic group into LD tag SNP selection for one or more different ethnic groups. To evaluate LD relationships between SNPs, a user can use not only pair-wise LD data calculated from HapMap genotype data for 11 populations in HapMap Phase III, but also has the option to use pair wise LD based on all dbSNP genotype data for each of five population groups (African American, Asian, European, Hispanics and sub-Saharan African). dbSNP genotype data includes all deposited HapMap data as well as additional SNPs, individuals and ethnic groups. dbSNP includes genotype data from many different genotyping and resequencing efforts on sometimes overlapping sets of individuals. We combined genotypes for individuals of the same ethnic group. If multiple submitters genotyped the same SNP in the same person and the genotype calls are inconsistent, we
