SNPs that were not actually typed by the genotyping platform. This approach of common controls and combined case groups used as controls was also employed by the WTCCC in its smaller study of 14,500 nonsynonymous SNPs in four autoimmune diseases, and in dense genome-wide genotyping of African cases of tuberculosis and malaria (35, 36). The Wellcome Trust recently announced plans to conduct genome-wide genotyping in 120,000 additional people to identify variants related to 25 diseases and traits using the same approach (37).
