Association between ADAM33 polymorphisms and adult asthma in the Japanese population

Background: ADAM33, a member of the ADAM (a disintegrin and metalloprotease) family, is a putative asthma susceptibility gene recently identified by positional cloning. It is important to know whether the association exists in ethnically diverse populations. Objective: To assess whether genetic functional variants of ADAM33 relate to the susceptibility or some phenotypes in adult patients with bronchial asthma in a Japanese population. Methods: We searched for single nucleotide polymorphisms (SNPs) in ADAM33 by PCR-directed sequencing and identified 48 SNPs. Fourteen SNPs were selected with regard to the LD pattern, and genotyped by Taq-Man and PCR-RFLP methods. We conducted an association study of ADAM33 with 504 adult asthmatic patients and 651 controls, and haplotype analyses of related variants were performed. Results: Significant associations with asthma were found for the SNPs T1 (Met764Thr), T2 (Pro774Ser), S2 and V - 3 (with the lowest P-value for T1, P = 0.0015; OR 0.63). We analysed the haplotype using these four polymorphisms, and found a positive association with haplotype CCTG (P = 0.0024). Conclusion: Our results replicate associations reported recently in other ethnic populations, and suggest that the ADAM33 gene is involved in the development of asthma through genetic polymorphisms.