Génétique de l'asthme et des allergies

Asthma and allergic diseases are conditions with variable clinical presentations that run in families. The positional cloning of five new susceptibility genes (ADAM33, PHF11, DPP10, GPRA, and TIM1) and the (sometimes inconsistent) association of increased susceptibility to asthma with variants of more than 60 genes suggest that genetic heterogeneity underlies asthma. Many of these polymorphic genes are involved in innate immunity to microbial factors, the initiation of a polarized T-cell response to common allergens, the expression of the IgE Fc receptor, and the production of and response to pro-inflammatory mediators, or their expression is limited to the bronchial mucosa. Genetic inheritance of alleles of modest effect, epigenetic allele-specific gene expression, interactions among genes, and between genes and environmental triggers appear to drive the onset and severity of asthma.