Depending on the genetic architecture of each disorder, one or more primary analyses could have sufficient power to detect genomewide significant evidence for association. For example, the largest analyses, with approximately 10,000 cases and 10,000 controls, would have 80% power to detect a SNP with a GRR of 1.152 with p < 5 × 10−8, assuming direct association with an allele with a frequency of 0.25, and log-additive inheritance, or 57% power for indirect association with an r2 of 0.8. Power would be reduced for smaller samples or for less common alleles or recessive effects. Note that if there are many risk alleles in the genome with a sufficient effect size, there would be substantial power to detect at least one of them. We expect to complete interim meta-analyses during 2008 and final analyses within 2009. Updated results will be posted on the PGC website (http://pgc.unc.edu).
