The clustering of individuals for PC1 and PC2 corresponded to self-reported regional and ethnic origins (Figure 1A and 1B). This is best illustrated when considering only those participants with the same grandparental country of origin and those individuals that indicated Ashkenazi Jewish ancestry (Figure 1B). Similar to our previous studies using smaller sets of SNPs, the clustering of individuals of Ashkenazi Jewish ancestry does not correspond to grandparental European country of origin, which was diverse [6].
