Genome-wide association analyses (GWA) were performed at the cohort level according to a pre-specified analysis plan (Standard Operating Procedures; SOP). Each cohort uploaded sex-specific and combined GWAS results to the BroadABC server as input for the meta-analyses. All analyses were restricted to samples of European ancestry. For sex-pooled analysis of the X chromosome, males were treated as homozygous females. Quality control (QC) and meta-analysis of the GWA summary results were performed by two independent analysts (J.J.T. & A.J.), following a strict analysis protocol. Further details on the SOP analysis plan and QC are provided in the Supplementary Information (Chapter 3) and on the website of BroadABC, http://broadabc.ctglab.nl/.
