Molecular genetic analysis of polymorphisms pertaining to the susceptibility to chronic asthma in Egyptian patients

Background: Asthma is a multifactorial inflammatory disorder that might result from the interaction of multiple genes and environmental factors. Several studies of genetic epidemiology have reported the association of cytokine genes with asthma among various populations. However, the results are inconsistent and inconclusive. Objective: To determine the association of cytokine gene polymorphisms with asthma susceptibility in adult Egyptian cases. Subjects: The study included, 50 adult Egyptian asthmatic cases with a mean age of 53.62± 14.61 years in addition to 98 healthy individuals as control. For all participants, DNA was isolated from peripheral blood samples and analyzed for TNF-alpha-308 G A, IL-10-1082 G A, IL-6-174 G C and IL-1Ra VNTR polymorphisms. Results: The comparison between the cases and controls has showed significantly higher frequency of the genotypic polymorphisms: IL-10-1082 AG + GG (dominant mode) (76.1% vs. 91.8%, p= 0.01, OR =0.3, 95% CI (0.1–0.7), TNF-alpha-308 GA +AA (dominant mode) (72.0% vs. 93.9%, p =0.001, OR= 0.17, 95% CI= 0.06–0.47) and IL-1RA VNTR heterozygous genotype A1A2 (90.0% vs. 58.8%, p= 0.0003). Otherwise, compared to controls, cases showed statistically non-significant frequency of genotypes corresponding to IL-6-174 CC + GC vs. GG (dominant mode) (92.0% vs. 94.9%, p=0.5, OR = 0.6). Conclusions: The IL-10, TNF-alpha and IL-1Ra allelic variants showed a potent association with chronic asthma among Egyptian cases that might be used as markers with a potential impact on prophylactic and or therapeutic measures for asthma control. Whereas the IL-6-174 allelic variants showed no association with chronic asthma among Egyptian cases.