We first assessed whether the “risk allele” of each SNP was associated in the same direction (odds ratios>1) in each ethnic group. Whereas the null hypothesis is that 50% of “risk” alleles would trend in the same direction, we observed from 12 (63%; P = 0.18; binomial probability) in European Americans to 19 (100%; P = 1.9×10−6) in Japanese Americans. The number of these associations that reached nominal significance (P<0.05) ranged from 3 (P = 0.067; binomial probability) in Native Hawaiians to 10 (P = 5.9×10−9) in Japanese (Table 2). For the majority of alleles with positive associations, odds ratios for homozygous carriers were greater than for heterozygous carriers in each population, which provides support for their associations and allele dosage effects (Table S2). In African Americans, results were similar after adjustment for percent European ancestry (Table S3). Adjustment for education, a proxy for socio-economic status (SES) and European ancestry, did not influence the results (Table S4) [23].
