Genetic basis of IgE responsiveness: relevance to the atopic diseases

Genetic analysis of 170 subjects in 11 extended Amish families revealed evidence for linkage of five markers in chromosome 5q31.1 with a gene controlling total serum IgE levels. No linkage was found between these markers and specific IgE antibody levels. Analysis of total IgE within a subset of 128 IgE-antibody-negative sib pairs confirmed evidence for linkage to 5q31.1, especially IL4 (p = 4 x 10(-6)). These and other data suggest that IL4 or a nearby gene regulates IgE production in a non-antigen-specific (noncognate) fashion and provide evidence for a possible link between asthma and the IL4 gene.