Aetiology of asthma

Asthma is complex, heterogeneous disease that is often associated with atopic sensitization in children. Asthma is believed to arise as a result of interactions in early life between environmental exposures and genetic predisposition. Estimates from twin studies suggest that asthma has a high heritable component. Large increases in childhood asthma prevalence were described in the United Kingdom and similar developed countries in the last few decades of the 20th Century. This change was too rapid to be explained by genetic shift and so there has been an intensive search for modifiable environmental factors that are causally related to the development of asthma in children. Although a large number of biologically plausible factors have been suggested, most have only modest effects on disease risk. New technologies to enable the study of genes and environment in relation to disease risk (-omics) may reveal new insights into asthma aetiology that could pave the way for primary prevention.