ENDOTHELIAL NITRIC OXIDE SYNTHASE POLYMORPHISM IN CHILDREN WITH BRONCHIAL ASTHMA
Asmaa Ismail Ahmed Ali and Azza Kamal Abdel Megid
Departments of Clinical and Chemical Pathology, and Pediatrics, Faculty of Medicine Cairo University
Background: Endothelial nitric oxide synthase(eNOS) is an enzyme that is extensively present in the air ways. Recent studies demonstrate increased nitric oxide production in bronchial asthma and suggest that polymorphisms of eNOS gene may play a role in the pathogenesis of asthma.
Aim of the work: To study any association between the 27 bp-variable number tandem repeat (VNTR) in intron 4 of eNOS and the development of bronchial asthma in Egyptian children.
Patients and Methods: Thirty five children with bronchial asthma were compared to twenty eight healthy children as a control group. Polymorphism of the 27-bp insertional VNTR of eNOS was studied by polymerase chain reaction (PCR).
Results: Results showed that b/b genotype was significantly higher in healthy children than in asthmatic children (p=0.034). Also there was a significant increase in the frequency of a allele distribution in asthmatic children than the healthy control children (p=0.037).Analysis of the odds ratio revealed that the a/a genotype showed 3.41 times increase in the risk of developing asthma with a 95% confidence interval of (1.09 -10.70) Also having one a allele(a/b genotype) showed 3 times increase in the risk of developing asthma with a 95% confidence interval of (1.03-8.85).
Conclusion: The 27-bp insertional VNTR of endothelial nitric oxide synthase seems to be implicated in the development of asthma.