implemented in the Family Based Association Test (FBAT) [Laid et al., 2000], even though such family-based designs diminish statistical efficiency. In population-based association studies, several statistical methods have also been developed to detect population stratification and to account for its effect on testing [Pritchard and Rosenberg, 1999; Devlin and Roeder, 1999; Bacanu et al., 2000; Shmulewitz et al., 2004; Price et al., 2006; Zang et al., 2007].
