Objective: To investigate the association between variants of IL13 gene and FA and FA related phenotypes in the Japanese population.
Methods: We re-sequenced the IL13 gene region by PCR-directed sequencing. Four tag SNPs were selected using the Tagger algorithm and genotyped by Invader methods. We performed association studies of FA using two independent Japanese populations (1st population, 603 cases and 1004 controls; 2nd population 282 cases and 904 controls). Among the 1st FA population, a total of 182 subjects have bronchial asthma.
Results: We found a total of 17 variants including a non-synonymous substitution (rs20541; Arg144Gln). We observed a significant association at rs20541 (meta-analysis, combined P = 1.33×10-7; OR, 1.39; 95% CI, 1.23-1.57). In further analyses of patient subgroups, we observed a strong association between rs1295686 and FA with bronchial asthma (P = 2.44×10-6; OR, 1.74; 95% CI, 1.38-2.19).
Conclusions: rs1295686 of IL13 gene is significantly associated with FA in the Japanese population. Although further genetic and functional analyses are needed, our findings could help elucidate common genetic factors for bronchial asthma, atopic dermatitis, and FA.