There are no set criteria for creating maximally informative polygenic scores [39], and so we created a series of scores using p-value thresholds ranging from 0.05 to 0.50. Table 1 summarizes the number of SNPs meeting each threshold in the ALSPAC sample, as well as the number and percent of those SNPs that were available in the FinnTwin12 sample. Previous work using polygenic approaches indicates that pruning for linkage disequilibrium (LD) does not substantially change the results [19,40]. In view of this, we chose to incorporate all SNPs meeting each polygenic threshold into our scores.
