Figure 1 shows the power of each of the tests of association as a function of the percentage of phenotypic variation explained by causal variants in the 50 kb region, assuming the trait mean is determined by the presence or absence of minor alleles at any of the causal variants. Results for two models are presented here, each assuming a total MAF of 5% for all causal variants in the region: (a) the maximum MAF of any individual causal variant is 0.5%; and (b) the maximum MAF of any individual causal variant is 2%. Model (b) incorporates fewer and, on average, more common causal variants than does (a), and thus represents a lower degree of allelic heterogeneity. Supplementary Figures 1 and 2 present power for a wider range of association models encompassing intermediate levels of allelic heterogeneity, where trait means are determined by the presence or absence of minor alleles at any causal variant, and by the proportion of causal variants at which a minor allele is present, respectively.
