Extended Data Fig. 7: Power calculations for rare variant discovery at the CHRNA5 GWAS locus.
From: Rare coding variants in CHRNB2 reduce the likelihood of smoking
Assuming an 80% power and P value of 5e-8, detectable effect sizes at various minor allele frequency values were calculated for the current sample size of cig-per-day (the smoking trait most associated with CHRNA5 locus) as well for a series of sample sizes up to 1 million. The observed effect sizes for pLOF only burden and pLOF and missense burden associations of CHRNA5, CHRNA3 and CHRNB4 are plotted; all the points lay below the red line, which marks the detection limit of our current sample size, suggesting that we are underpowered. Based on the intersections of the grey lines with the points marking the observed effect sizes, we can approximately guess what sample size will be required to detect these burden signals at P value 5e-8.
