Dominant inheritance of atopic immunoglobulin-E responsiveness.

The familial occurrence of atopy, defined by skin prick test responses and serum immunoglobulin-E (IgE) titres to common inhaled allergens, was studied in 239 members of 40 nuclear and 3 extended families. 90% of the atopic children in the nuclear families had at least one demonstrably atopic parent. In each extended family, atopy was vertically transmitted, and 31 of 47 (66%) offspring of marriages between atopic and unaffected parents were atopic. Of the designated atopic subjects, 83% admitted to symptoms suggesting atopic disease but only 30% regarded themselves as having any such disorder. It is suggested that atopy, the propensity to produce IgE in response to common, usually inhaled, allergens, is inherited as an autosomal dominant character but that its clinical expression depends on interaction with other factors.