As in the original study (Karlsson Linnér et al. 2021), we estimated individual SNP effects on the latent EXT-minus-23andMe factor with Genomic SEM, which we refer to as the EXT-minus-23andMe summary statistics. We then evaluated the loss of signal at the factor level. We expect the loss of power to be more noticeable at the level of individual loci compared to the follow-up analyses presented below, which aggregate genetic signal across larger sets of SNPs or genome wide. Lastly, we examined the concordance of GWAS coefficients on the latent factor per the three-check procedure outlined in Step 1.
