Association between atopy and variants of the β subunit of the high-affinity immunoglobulin E receptor

The β–subunit of the high–affinity IgE receptor (FcεRI–β) on chromosome 11 is maternally linked to atopy, the state of enhanced IgE responsiveness underlying allergic asthma and rhinitis. We have identified a common variant of FcεRI–β, lle181Leu within the 4th transmembrane domain. Leu181 shows significant association with positive IgE responses in a random patient sample. Amongst 60 unrelated nuclear families with allergic asthmatic probands, Leu181 is identified in 10 (17%), is maternally inherited in each, and shows a strong association with atopy. Our data indicate that FcεRI–β , subject to maternal modification, may be the atopy–causing locus on chromosome 11q.