The GWA analyses were performed by each group separately. Associations between the binary phenotype and the genotypes were tested genome-wide using a logistic regression model including covariates (see above). For family-based samples, familial relatedness was taken into account by using a sandwich correction as implemented in PLINK.35 The analyses plan can be found in Supplementary Information 3. It should be noted that some groups did do the analyses in a slightly different manner based on the characteristics of their sample. The analyses plan that was send to the participating groups is included in Supplementary Information 3. It should be noted that some groups did do the analyses in a slightly different manner based on the characteristics of their sample. Supplementary Table 2 lists the program used by each group.
