Data management and quality control filtering are described in the Supplementary Methods online. Case-control matching, by gender and ancestry, followed by association analyses by conditional logistic regression on gender-ancestry strata in the matched datasets (see Supplementary Table 1 online) were performed using GEM13. The GEM analysis is described in more detail in the Supplementary Methods online. The genomic control inflation factor was computed14. SNPs with nominal P values < 5×10−8 were considered to have genome-wide significant evidence for association27.
