Increments in marker density from 630,000 to 1,000,000 and increases in sample sizes from n = 400 to n = 2,000 samples in case and control improve power (Figure 5). However, the steep relationships between power and effect sizes are also found in these simulations. Such results underscore the distinctions that we have made above concerning analytic approaches to “oligogenic” disorders in which variants at individual gene loci produce relatively large differences in risk vs “polygenic” disorders in which the effects at each locus are likely to be modest.
