Linkage between severe atopy and chromosome 11q13 in Japanese families.

Atopy, characterised by allergic asthma and rhinitis, is due to increased IgE responses to common aeroallergens. An Oxford group has described maternal inheritance of atopy, where there is significant linkage between IgE responsiveness and a VNTR marker D11S97 and a CA microsatellite within a candidate gene, the high affinity IgE receptor beta subunit (Fc epsilon RI beta), on chromosome 11q. Attempts at independent replication have produced conflicting results. We therefore recruited 270 atopic asthmatic probands in a Japanese community population for genetic linkage analysis. Four families, each with more than 15 meioses and a clear phenotype for atopy, were selected for genetic analysis. Atopy was defined as presence of all of raised total IgE, positive RAST and skin tests to three or more aeroallergens; non-atopy, as absence of all these criteria. Linkage analysis showed a maximum two-point lod score of 9.35 for D11S97 and Fc epsilon RI beta under the assumption of unequal rates of maternal and paternal recombination. Two families showed close genetic linkage with Fc epsilon RI beta with a pattern of maternal inheritance. These results from a Japanese population provide further evidence for genetic linkage between severe atopy and chromosome 11q13 and the likelihood of genomic imprinting at the locus.