CEU, YRI and CHB/JPT individuals as reference samples. Of the 317,503 markers on the HumanHap300 BeadChip, 2,635 were deemed unusable due to lack of polymorphism, severe deviation from Hardy–Weinberg equilibrium (P < 1 × 10−10), low yield (<95% in either cases or controls) or allele frequency differences between the typing centres (P < 1 × 10−7); 314,868 markers, then, remained for analysis.
