On the basis of MAFs and associated genotypic risks we estimate the 5p15.33 and 6p21.33 variants individually account for ~1% of the excess familial risk, with the 15q25.1 locus having a much greater impact (~5%). To gain insight into the basis of the inherited risk of lung cancer in general we estimated the power of our analyses to identify disease-associated loci with different MAF which would account for 1% of the familial risk (Figure 3). With the UK-GWA study we had greater than 90% power to harvest variants with similar characteristics to 15q25.1. However, we only had ~30% and 40% power to identify variants such as 5p15.33 and 6p21.33 which have much weaker effects. Using all four datasets our meta-analysis was well powered to identify common variants (MAF >0.15), provided each accounts for ≥ 1% excess risk. Clearly for variants such as 5p15.33 power still remained limited.
