Basing our analyses on the sub-sample with GWA data enabled us to correct for cryptic relatedness and population structure via PC analysis (see Statistical Analyses). The genetic association results in the full genotyped sample and the sub-sample with GWA were not materially different. Since Weedon et al, 2008 [4] used a different platform (Affymetrix 500 K chip) for genotyping, we could not directly obtain all the SNPs they identified from our GWA data. We could have imputed them but preferred to use directly genotyped SNPs.
