Quantile-Quantile plots for test statistics for SNPs passing quality control in each dataset. Figure shows -log10 (p-value) of observed association statistics in Y-axis, compared to -log10 (p-value) of the association statistics expected under the null hypothesis of no association in X-axis. The solid line represents concordance of observed and expected values. The genomic inflation factor, λ, is shown for each dataset. A) Ashkenazi Jewish (λ = 1.003), b) NINDS (λ = 1.026), and c) CIDR/Pankratz et al 2009(λ = 1.031).