Nat. Genet. 42, 949–960 (2010); published online 10 October 2010; corrected after print 12 October 2011

In the version of this article initially published, there were errors in Table 1. Specifically, for eight SNPs, the effect allele frequencies were reversed. The correct effect allele frequencies for rs9491696, rs984222, rs4846567, rs1011731, rs718314, rs1294421, rs6795735 and rs2076529 are 0.480, 0.635, 0.717, 0.428, 0.259, 0.613, 0.594 and 0.430, respectively. These errors have been corrected in the HTML and PDF versions of the article.