An IL13 coding region variant is associated with a high total serum IgE level and atopic dermatitis in the German Multicenter Atopy Study (MAS-90)

Background: Allergic diseases are one of the major causes of morbidity in the developed countries today, and the prevalence of these diseases is increasing steadily. Study of total serum IgE level is important in understanding the genetics of allergic diseases because IgE levels are considered to be a crucial pathogenic component. IL-13 plays an important role in the induction of IgE synthesis and in the pathogenesis of allergic diseases. Objective: We sought to examine potential variation at the IL13 gene and estimate its effect on elevated IgE level and atopic dermatitis (AD). Methods: We conducted mutational analyses of the IL13 gene by using single-stranded conformation polymorphism and DNA sequencing. Case control studies for high-IgE phenotype and AD were performed by using subjects from the German MAS-90 cohort. Results: A novel IL13 coding region variant at 4257 bp (G to A, fourth exon) was identified. Case control studies of a German sample from the MAS-90 cohort showed significant associations between the presence of the A allele and two atopic phenotypes: high IgE (odds ratio, 2.38; 95% confidence interval, 1.35-4.21; P = .0026) and AD (odds ratio, 1.77; 95% confidence interval, 1.06-2.96; P = .03). Conclusion: This IL13 coding region variant may be involved in the pathogenesis of AD and high total serum IgE level in a study population of white subjects.