[Association study of bronchial asthma with polymorphisms of IL-4 and IL-4R receptor genes]

To assess the association of polymorphisms of IL-4 gene (rs2243250, rs2243283) and IL-4R gene (rs1805012, rs1801275, rs1805010) with susceptibility to asthma among ethnic Chinese in Qingdao.

For 400 asthma patients and 200 healthy subjects, above polymorphisms were detected with SnaPshot method.

For rs1805012, the frequency of TC genotype in the asthma group was significantly lower than the control group (8.8% vs. 15.5%, χ (2)= 6.498, P= 0.039), and so were the frequencies of TC+ CC genotypes (9.0% vs. 15.5%, χ (2) = 5.522, P= 0.019) and the C allele (4.6% vs. 7.7%, χ (2) = 4.729, P= 0.039). No significant difference was detected between the two groups in the frequency of the remaining four polymorphisms or the haplotypes formed by rs2243250 and rs2243283 (All P> 0.05).

This study has indicated that rs1805012 polymorphism of IL-4R gene is associated with asthma in ethnic Han Chinese from Qingdao region. TC+ CC genotypes have a protective role against asthma compared with TT genotype. However, polymorphisms of IL-4 gene are not associated with susceptibility to asthma.