As reported previously [22], [23], eQTLs were often found with the expression of more than one gene underlying a GWAS signal (Table 3). For example, the rs7216389-T allele on chromosome 17q was reported to increase asthma risk with an odds ratio (OR) of 1.45 [10]. This SNP was significantly associated with the expression levels of four genes, ORMDL3, GSDMA, GSDMB, and CRKRS (Figure 2a). Although ORMDL3 was originally suggested [10] to be the gene mediating rs7216389-T's association with asthma, this gene demonstrated the weakest eQTL signal of the four genes in our dataset. Rs7216389-T was positively associated with expression levels of ORMDL3 (P = 1×10−7), CRKRS (P = 1.76×10−9) and GSDMB (P = 4×10−15), consistent with the results of Moffat et al. [10] However, this same allele was inversely related to the level of expression of GSDMA (P = 8.78×10−25) (Figure 2b). The strongest eSNP in the 17q asthma susceptibility locus was rs3859192 located in intron 6 of the GSDMA gene governing the expression levels of this gene (P = 3.55×10−151) (Figure 2b).
