Linkage disequilibrium plots and haplotype blocks for individuals of European Ancestry were generated from publicly available HapMap (phase II) data using the software program Haploview v4.1 (Barrett et al., 2005). Pair-wise SNP |D′| values (× 100) of linkage were computed using the 4-gamete rule. High D′ values indicate SNP pairs without evidence of extensive recombination (i.e., 4-gamete rule for haplotype block characterization with at least one 2-SNP haplotype having a frequency <0.02). In other words, SNPs with high D′ values indicate that markers are good surrogates for each other, likely to be transmitted together, and therefore likely to capture similar genetic variance.
