The magnitude of the estimated effect on untransformed FEV1 of rs10516526 in GSTCD was 52 ml per copy of the G allele (frequency, 0.06). This is equivalent to about 3 years of FEV1 decline in the nonsmoking population35. Allelic effect sizes on FEV1 of the more common variants (minor allele frequencies ~0.4) were 19–23 ml for rs3995090 in HTR4 and rs2571445 in TNS1. Individually, the five loci we describe account for a small proportion (0.07%–0.14%) of the variance in FEV1 and in FEV1/FVC (Table 2) in the general population.
