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 t he developed countries today, and the prevalence of these diseases is incre asing steadily. Study of total serum IgE level is important in understandin g the genetics of allergic diseases because IgE levels are considered to be a crucial pathogenic component. IL-13 plays an important role in the induc tion of IgE synthesis and in the pathogenesis of allergic diseases. Objective: We sought to examine potential variation at the IL13 gene and es timate 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 Ge rman 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 c ohort showed significant associations between the presence of the A allele and two atopic phenotypes: high IgE (odds ratio, 2.38; 95% confidence inter val, 1.35-4.21; P = .0026) and AD (odds ratio, 1.77; 95% confidence interva l, 1.06-2.96; P = .03), Conclusion: This IL13 coding region variant may be involved in the pathogen esis of AD and high total serum IgE level in a study population of white su bjects.