We performed the GREML analysis4 in GCTA8 to estimate the variance explained by the selected SNPs (h2g) in each of the five validation studies. This method fits the effects of a set of SNPs simultaneously in a model as random effects and estimates the genetic variance captured by all the fitted SNPs without testing the significance of association of any single SNPs. We combined the estimates of h2g from the five studies by the inverse-variance approach, i.e. Σi (h2g(i)/SE2i)/Σi (1/SE2i).
