A modified two-stage approach for family-based genome-wide association studies.

Genome-wide association studies can provide researchers some reference on gene mapping of complex trait, a key point of which is how to improve the power of association test. Recently, two-stage approaches are widely used to genome-wide association analysis. In the first stage, a screening test is used to select markers, and in the second stage, a family-based association test is performed based on a smaller set of the selected markers. Here, we modify an existing two-stage approach and propose a new test statistic for the association analysis. Simulation studies are conducted to compare the type I error rates and powers of the proposed approach with those of the existing two-stage approaches. Simulation results show that the new two-stage approach has greater power than the other two-stage approaches to some extent.