Population structure in genetic studies: Confounding factors and mixed models - Fig 4

Expected distribution of p-values in a typical (A) Manhattan plot, (B) cumulative p-value distribution, and (C) Q–Q plot. Circles in (B) and (C) denote where the median p-value (red line) falls on the graph in comparison to the expected median p-value (yellow line). Here, the median falls close to 0.5, suggesting that population structure is not affecting association results or has been corrected for in the model. Q–Q, quantile–quantile.