and controls to infer ancestry. Two markers did not pass the HWE test. They are SNP N4 (p-value = 7.6×10−5) only in the control sample and SNP A4 (p-value = 2.3×10−6) only in the AD-only sample. Since causal variants in the affected sample could cause a failure of the HWE test, SNP A4 in the AD-only sample could be a risk-influencing variant. As for SNP N4, it fails the HWE test only in the control sample, and we kept this marker in the analysis for comparison purpose. Genotyping errors were detected and resolved (details described in Yang et al. (2007).
