Individuals were genotyped on the following platforms, with the respective genotyping centers indicated in parentheses: NFBC—Illumina 370duo Chip (Broad Institute, Cambridge, MA, USA), YFS—Illumina 670K Custom BeadChip, HBCS—Illumina 610K Quad Chip (Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, UK), QIMR samples—Illumina 317K (Finnish Genome Centre, Helsinki, Finland); Illumina HumanCNV370-Quadv3 (Center for Inherited Disease Research, Baltimore, MD, USA); Illumina Human610-Quad (DeCode, Reykjavik, Iceland) and Affymetrix 6.0. (TGen, Phoenix, AZ, USA). Rather than combining genotype data from different platforms in a joint analysis of all four cohorts, we used meta-analytic techniques to combine results from association analyses performed separately by cohort (see below).
