We have been impressed by the variability in the detailed distribution of linkage disequilibrium across different genomic loci in different samples [130, 131]. We have also been impressed by the possibilities that approximations of this variability could be modeled, on average, by simple functions. Under these circumstances, estimates of effects of sample size, locus-specific effect sizes for the underlying functional alleles, genetic heterogeneity, penetrance and marker density can produce reasonable models that can allow assessments of the effects of variation in these parameters on power.
