combining p values, which aggregates the evidence for all SNPs simultaneously. Since odds ratios must be in the same direction as our GWAS to count as replication, one-sided p values were used in the analysis. Enrichment was tested in the ADHD genetics consortium and deCODE samples separately, and in both data sets combined (see the online data supplement). A meta-analysis of all three samples (Cardiff ADHD GWAS, ADHD genetics consortium, and deCODE) was also performed on each of the top 100 SNPs (without pruning) separately.
