Building on the work on genome-wide multivariate meta-analysis by Baselmans et al. (2019), we have developed a method to derive GWAS summary statistics for a genetic principal component of multiple GWAS phenotypes derived from samples of unknown degrees of overlap using univariate summary statistics for the individual phenotypes. In this Rmarkdown document, we evaluate the method and examine the origin for "mirrored" patterns observed in the effect sizes created with this new method.

Building on the work on genome-wide multivariate meta-analysis by Baselmans et al. (2019), we have developed a method to derive GWAS summary statistics for a genetic principal component of multiple GWAS phenotypes derived from samples of unknown degrees of overlap using univariate summary statistics for the individual phenotypes. In this Rmarkdown document, we test and validate this approach.