single subject having the highest call rate from each cluster. Since IBD estimates may be inflated in the presence of population stratification, we used the KING program (Manichaikul et al. 2010) to identify clusters among African American subjects. The KING program was designed specifically to circumvent the inflation of IBD estimates due to population stratification (Manichaikul et al. 2010). We used the IBD threshold of 10 % and the KING kinship coefficient threshold and retained the single subject having the highest call rate from each African American relative cluster.
