We next calculated a summary risk score comprised of an unweighted count of the 19 risk-associated alleles. The average increment in risk per allele was generally similar in all populations, except Japanese Americans, where the effect of each allele was nearly double that observed in Europeans ((odds ratio, 95% confidence interval): African Americans, 1.09, 1.05–1.12; (P = 3.0×10−6); Native Hawaiians, 1.10, 1.06–1.15 (P = 1.2×10−5); European Americans, 1.11, 1.06–1.17 (P = 1.2×10−5); Latinos, 1.12, 1.09–1.14 (P = 7.5×10−19); and, Japanese, 1.20, 1.17–1.24; (P = 7.0×10−32); Phet = 3.8×10−4). Results were similar when limiting the analysis to individuals with complete genotype data for all variants and when including only those markers associated with risk (at P<0.10) (Table S5). Individuals in the top quartile of the risk allele distribution were at 1.6 (African Americans, P = 5.3×10−4) to 3.1-fold (Japanese Americans, P = 7.9×10−26) greater risk of diabetes compared to those in the lowest quartile (Table 3).
