Second, the largest GWAS to date had essentially 100% power to identify common genetic variants with GRR > 1.15 (minor allele frequency > 0.10) or GRR > 1.19 (minor allele frequency > 0.05). We can thus exclude common genetic effects akin to those for APOE and Alzheimer’s disease (i.e., GRR of 3.7 for APOE*ε4 vs. ε3). 25 We can also conclude that the GRRs reported in many of the 24 common variant studies in Table 1 (often >1.5 and >2 for five genes) are inconsistent with what we now know about GRRs for common variation (Table 2, often for the same genetic marker reported in the initial study). Some common variants in Table 2 (e.g., the KCNN3 CAG repeat or complex haplotypes in NRG1) may not have been well-captured in SNP arrays; however, this criticism is mitigated by the lack of evidence from the SZGene meta-analyses for the same variants.
