By performing a large GWAS study on adult height, a highly heritable polygenic trait, we have provided answers to several current questions of relevance to the genetic study of polygenic diseases and traits. First, we showed that by conducting larger GWAS, we can identify SNPs that explain a substantial proportion of the heritability attributable to common variants. As hypothesized by Yang et al. (2010), the heritability directly accounted for by variants identified by GWAS and inferred by whole-genome estimation approaches are converging with increasing sample size. The variance explained by genome-wide significant SNPs has increased from 3–5% with discovery samples of ~25,000 (ref. 19) to 10% with a discovery sample size of ~130,000 (ref. 6) to 16% with a discovery sample size of 250,000 (this study), and the variance explained from all captured common SNPs is ~50%4,5. The variance explained by genome-wide significant SNPs on a chromosome is also proportional to its length, consistent with the conclusion made by Yang et al.5 using all SNPs (Supplementary Fig. 9). Our new results show that ~21%, ~24% and ~29% of phenotypic variance
