ADAM33 gene polymorphisms in Southwestern Iranian patients with asthma

Objective(s): Asthma, the most frequent chronic respiratory disease, results from a complex interaction between multiple genes and environmental factors. To date, more than 100 candidate genes and single nucleotide polymorphisms (SNPs) have been reported to be associated with asthma. One of the discovered genes related to asthma is ADAM33. However, the relationship between ADAM33 gene polymorphisms and asthma is controversial. The aim of this study was to investigate the association between four ADAM33 gene SNPs and susceptibility to asthma in patients from southwestern Iran. Materials and Methods: ADAM33 gene polymorphisms at positions T+1 (rs2280091), T1 (rs3918396), S1 (rs2280089), and F+1 (rs511898) were examined in 150 patients with asthma and 149 age- and sex-matched healthy controls with a PCR-RFLP method. Results: There were no differences between patients and controls in allelic or genotype frequencies of ADAM33 SNPs. We found no associations between allelic or genotype distribution of the SNPs and spirometry indices, concomitant involvement of other allergic diseases, or exposure to cigarette smoke. In contrast to H4 haplotype, which appeared to be protective against asthma, inheritance of H2 and H3 haplotypes increased the risk of asthma up to 2-3 folds. Conclusion: ADAM33 gene polymorphisms appear to play a partial role in asthma susceptibility, investigation of expression changes in this gene in response to environmental factors or the local formation of a soluble form of the molecule in the lung can be helpful to elucidate the impact of this molecule in the induction of asthma.