The role of R576Q polymorphism of interleukin-4 receptor alpha gene in atopy: results of a family-based study design.

INTRODUCTION: There is strong evidence that the R576 allele of interleukin-4 receptor alpha gene (IL-4R) might predispose to atopy. To test this hypothesis, we examined the association between the R576Q polymorphism and atopy in a Polish population using the family-based study design. MATERIALS AND METHODS: 44 atopic patients (age range from 11 to 34 years) with pollen and house dust mite allergy or/and mild asthma together with both parents were studied. The R576Q polymorphism of the IL-4R gene was genotyped in each patient and both parents, respectively, using the PCR-based protocol. The results were analyzed by the transmission disequilibrium test (TDT). The total IgE serum level, allergen-specific IgE to the common aeroallergens, IL-4, and sIL-4Ralpha were assessed in each patient and both parents. RESULTS: In the TDT test the R576 and Q576 alleles were transmitted from the heterozygous parents to the affected offspring 20 and 15 times, respectively (McNemar test: p = 0.19). The results of the transmission disequilibrium test did not reach statistical significance. Thus, the R576 allele might contribute to the pathogenesis of allergic diseases in patients with high total IgE serum level (p < 0.05). A larger study group has to be studied to prove the observed linkage and association.