Association of IL4 gene polymorphisms with asthma phenotype

Background: Asthma is a major chronic disease, and a lot of studies indicate that it is on the rise worldwide. The implication genes responsible for this disease may indicate pathways for therapeutic intervention and information about the prognosis of children from asthma's family. Genetic risk factors may be useful for identifying subtypes of asthma. Several lines of evidence suggest that the IL-4 gene is involved in the development of atopic asthma. Objective: The objective of this study was to analyze the polymorphism -590 C/T IL-4 in the subgroups of patients with early-onset asthma (defined as asthma developing before 16 years of age) and later-onset asthma and in the group of population control.The genetic polymorphisms –590 C/T were studied by PCR-RFLP analysis Results: The frequency of -590 C allele of the IL-4 gene was significantly higher in the group of patients with asthma (p = 0.0366) as compared to the population group. The analysis of distribution of the -590 C/- genotype showed significant increasing of the frequency of this genotype in the group of patients with later-onset asthma (p = 0.0231) as compared to the early-onset asthma group of patients. According to odds ratio value (OR=4.2 [CI:1.658-11.014]) -590 C/- genotype of the IL-4 could be responsible for 4-fold increase in the risk of later-onset asthma. Conclusions: Asthma is caused by genetic and environmental factors and this chronic disease is genetically heterogeneous. Our data show that -590 C/T IL-4 polymorphism plays a role in disease formation and could be treated as a prognostic genetic marker of the risk of later-onset asthma.