The interleukin 4 receptor - polymorphism and allergic asthma in children

Allergic asthma is a multifactorial disease and although environmental influences are important in the development of asthma and other atopic disorders, there is also a strong genetic predisposition. Several genes and chromosome regions have been linked to atopy and asthma. IL-4 is the TH2-cytokine (T-helper) which contributes to allergic inflammation and plays a major role in immunoglubulin E (IgE) production. Its signal is conferred to the effector cells through binding to the _ chain of the IL-4 receptor.
Several polymorphisms of the IL-4R gene have been reported and the R576 allele shown to be a risk factor for atopy. To determine the role of the R576 allele in asthma, 56 atopic children with different asthma phenotypes were genotyped. We investigated the frequency of Q576R alleles and association of R576 allele with the clinical severity of asthma and with total serum IgE. The frequencies for the Q576 and R576 alleles in this group were 86% and 14% respectively. 40 patients were homozygous for Q576 allele, 15 patients had R576 allele and 1 patient was homozygous for R576 allele. Presence of R576 allele has a significant influence on total serum IgE concentrations. No correlation between R576 allele and asthma severity or coexistence of allergic rhinitis was found.