Genetics and epigenetics of childhood asthma

Asthma is a complex disorder caused by interaction of genetic and environmental factors. In the last decade a lot of genes related to asthma and atopy were discovered. Candidate gene studies showed the involvement of genes related to innate and specific immunity, and replicated examples of interaction of genes and the environment. New genes identified through positional cloning studies, such as ADAM33, revived the interest in the airway epithelium and mesenchyme as important structural cells in asthma. Most genome-wide association studies discovered genes related to asthma that functions at the interface of airway structural cells and inflammation, such as IL33, IL1RL1 and TSLP. Epigenetics refers to heritable changes in gene expression without changes in DNA sequence, and includes DNA methylation, histone modifications and microRNAs. Several environmental factors known to be relevant in asthma may influence epigenetic modifications, however, the specific role of epigenetics in asthma is not clear. The ultimate goal of research in (epi)genetics of asthma is to identify susceptible subjects, and to contribute to (preventative) interventions.