Genome-wide association analyses were performed at the cohort level according to a pre-specified analysis plan. Genotyping was performed using a range of common, commercially available genotyping arrays. The analysis plan instructed cohorts to upload results imputed using the HapMap2 CEU (r22.b36) reference sample37. We meta-analyzed summary association statistics from 59 contributing cohorts with a combined sample size of 298,420 individuals. Before meta-analysis, a uniform set of quality-control (QC) procedures were applied to the cohort-level summary statistics, including but not limited to the EasyQC38 protocol. All analyses were restricted to European-ancestry individuals.
