Association study of promoter polymorphisms within the NOS3 gene and allergic diseases

Background: Nitric oxide (NO) is an important mediator of physiologic and pathologic processes in the airways. On this basis, we hypothesized that polymorphisms in the NOS3 gene could be associated with the disease process. Methods: Two promoter variants (-786C/T and -691C/T) were examined in a Caucasian Czech population of allergic patients [n = 671, with a subgroup of asthmatics (n = 305)] and healthy controls (n = 334) using PCR-RFLP analyses. Results: NOS3 -786C/T and -691C/T were not associated with allergic diseases or asthma. However, the -786 variant was significantly associated with asthma in men (P < 0.01, P-corr < 0.05) but not in women. NOS3 -691C/T was found to be in strong linkage disequilibrium with -786C/T, and the distribution of combined genotypes was marginally different between the asthmatic and control men. Conclusion: Our results suggest that NOS3 gene variants may be one of the factors that participate in the pathogenesis of asthma in men. Copyright (c) 2006 S. Karger AG, Basel.