a, Expected derived allele frequency spectrum among 40 CEU chromosomes for different classes of genetic variation, on the basis of the estimated strength of purifying selection acting on each class (see text for details). The estimated value of γ, the average scaled population selection coefficient, is indicated in the legend for each class of variant: exonic (γ=−17, P < 10−30), intronic (γ=−8, P < 10−10), and intergenic (γ=−5, P < 10−30) CNVs. The P values are estimated using a Likelihood Ratio Test of neutrality (γ = 0). If we do not correct for incomplete ascertainment for these three classes of CNV we estimate γ to be −13, −7and −4, respectively. Similarly, if we consider only sites >1 kb, which have more complete ascertainment we estimate γ to be −15, −10 and −5, thus showing this ordering of classes of CNV to be robust. b, A CNV showing increased XP-EHH in analysis of merged SNP-CNV HapMap haplotypes; blue line and symbols, CEU-YRI; grey, CEU-CHB+JPT; green, CHB+JPT-YRI. The locations of potential functional variants are indicated by symbols: filled diamond, CNV; cross, non-synonymous SNP; x, synonymous SNP; triangle, UTR SNP. c, Linkage disequilibrium between CNV2659.1 (pink bar) and multiple sclerosis GWAS hit SNPs (pink diamonds). Near perfect linkage disequilibrium (r2 = 0.95) was observed with the top hit SNP (rs47049). Patterns of linkage disequilibrium between the CNV and other HapMap SNPs are shown with black points.