We applied this approach to 21,497 African Americans from the NHLBI CARe, WHI-SHARe, and AAPC projects, analyzing 12 quantitative phenotypes and 1 case-control phenotype. For height and BMI, we obtained h2 estimates of 0.55 ± 0.09 and 0.23 ± 0.06, respectively, which are larger than estimates of hg2 in these and other data sets but smaller than twin-based estimates of h2, consistent with inflation in twin-based estimates because of shared environment or epistasis. We also estimated the heritability of height for each chromosome and found a significant correlation between chromosome length and heritability (p-value < 0.003).
