We estimated the SNP-heritability (hg2) tagged by PIP>0.95 fine-mapped SNPs (which is likely to be close to the heritability causally explained by these SNPs, if most of the tagged SNP-heritability originates from PIP>0.95 SNPs). The hg2 tagged by PIP>0.95 SNPs captured a large proportion of the hg2 tagged by lead GWAS SNPs (median proportion=42%; Figure 2b, Methods, Supplementary Table 14). This proportion was substantially larger than the proportion of GWAS loci harboring PIP>0.95 SNPs (20%; see above), as fine-mapping power is higher at loci with larger causal effects (Supplementary Table 4). However, fine-mapped SNPs tagged a smaller proportion of total MAF>0.001 hg2 (median proportion=19%; Figure 2b, Methods, Supplementary Table 14), indicating that substantially larger sample sizes are required to comprehensively fine-map all heritable SNP effects.
