Chunk #92 — 7.0 Recommendations to Advance Endophenotype Genetics — 7.3 Adequate power to detect individual effects is crucial but almost never attained in existing endophenotype genetic association studies — 7.3.1. Power and sampling schemes in GWAS
nicotine metabolite cotinine, error in measuring the phenotype is reduced by half, and MAF for the variant is maximized at 50%, 1,465 participants are still required to have 80% power to detect a single genome-wide effect. The worst-case scenario is observed for educational attainment, where N=198,302 is required to return a single genome-wide significant effect for 80% power. N=148,475 is still required after error and MAF are optimized. Discovering more than a single effect clearly will require much, much larger samples.
