Atopy phenotype in subjects with variants of the b subunit of the high affinity IgE receptor

b) at this chromosome 11q location and atopy by maternal descent. The identification of this Background – FceRI plays a central role in atopy, thus genetic variants of FceRI-b variant DNA has proved problematic, perhaps because of protein/DNA binding at the site, may alter receptor function to enhance atopic responses and may manifest as a but the variants we report have been confirmed by direct DNA sequence analysis. In this study more severe atopic phenotype and more symptomatic atopic disease. The immunowe have compared the immunological and clinical features of atopy between the subjects with logical and clinical features of atopy in children with and without the Leu 181 variand without the Leu 181 variant, as genotyped in our previous study, and discuss the corant of FceRI-b were compared. Methods – Sixty British nuclear families, relation of various atopic characteristics with maternal transmission of the Leu 181 allele. including 10 families with the FceRI-b variant Leu 181, recruited via a young proband with atopic asthma were analysed for atopic parameters including total IgE, Methods specific IgE, and clinical atopic disorder. Sixty nuclear families ascertained through an Results – Compared with other children atopic asthmatic proband (aged between 5–25) (combined atopic and non-atopic subwith one other sibling and both parents availjects), maternally inherited Leu 181 was able for testing were examined. Of these, 10 associated with increased levels of total families had Leu 181 segregating, there were IgE (odds ratio (OR) 4.82, 95% confidence 13 atopic children with maternally inherited interval (CI) 1.02 to 27.66, p <0.01) and Leu 181 in these 10 families, and 122 children a positive IgE response to grass pollen age matched from the other 50 nuclear families. allergen (OR 7.45, 95% CI 1.56 to 35.52, p Atopy was defined as one of the following <0.005) but not wheeze (OR 1.97, 95% CI features or any of their combinations: positive 0.56 to 7.69), asthma (OR 2.25, 95% CI 0.65 skin prick test (greater than or equal to 2 mm to 7.85), or required medications (OR 0.95, above negative control), positive specific IgE 95% CI 0.29 to 3.14). There were trends RAST (class 1 or above), or raised total IgE for each atopic parameter to be more (greater than published normal values for chilmarked in atopic children with maternally dren or 100 kU/l for non-smoking adults). inherited Leu 181 than in atopic children without Leu 181. Children with maternal Leu 181 had significantly raised eosResults inophils but there was no difference in Of 13 children with maternally inherited Leu basophil levels compared with other atopic 181 11 had asthma or rhinitis, or both, and 10 children. had eczema. Significantly raised total IgE levels Conclusions – The Leu 181 variant of (OR 4.82, 95% CI 1.02 to 27.66, p <0.01) FceRI-b, or another identified variant in and positive skin prick testing to grass pollen linkage disequilibrium, may promote the allergen (OR 7.45, 95% CI 1.56 to 35.52, p development of atopy. <0.005) was found in the comparison between (Thorax 1997;52:654–655) the children with maternal Leu 181 and the other children (combined atopic and non