[Genetic background of bronchial asthma]

Abstract

Familial aggregations and genes for atopy, airway hyperresponsiveness, and serum IgE were studied in 69 members of five atopic asthmatic families spanning three generations. Atopy was found in 68%, bronchial asthma in 26%, airway hyperresponsiveness in 45%, and positive mite allergen in 59%. Both atopy and airway hyperresponsiveness were inherited in an autosomal dominant fashion, but were not related to each other. No linkage was found of HLA with atopy and mite positivity. T cell gamma receptor gene (7p15), IL-3, IL-4, and IL-5 genes (5q23), and postulated atopic gene (11q13) were all not linked to atopy. However, alle 2.5 kb of 11q13 showed an association with serum IgE level. The beta 2 adrenergic receptor gene (5q31-32) was linked to airway responsiveness to inhaled beta 2 adrenergic agonist, and was associated with the occurrence of bronchial asthma.