The nasal methylome and childhood atopic asthma

It has long been known that many diseases, like asthma, are the result of complex interactions between genes and the environment.  But how exactly do these two factors contribute to atopic asthma?  In the May 2017 issue of JACI, Yang and colleagues discuss the epigenetic factors involved in the development of childhood asthma (J Allergy Clin Immunol 2017; 139(5): 1478-1488).  They looked at nasal brushings from 36 inner-city children with asthma between the ages of 10 and 12 and compared them with nasal brushings from 36 children without asthma.  They then looked at patterns of methylation, a way that genes can be chemically modified in order to change their expression. They found that 186 genes were modified in this way.  The median percentage in methylation changes between allergic patients and non-allergic patients was 6.8%.  This is in line with previous research that shows that there are significant changes in methylation in other airway diseases like chronic obstructive pulmonary disease (COPD) and with cigarette smoking exposure.

This research is important, because it opens up new targets for research, diagnosis, and perhaps even treatment.  Future research can focus on what specific environmental changes lead to differences in genetic expression.  Additionally, because the normal bacteria in the nose affect methylation patterns, researchers may be able to look at which specific bacterial species impact gene expression. The authors speculate that the methylation markers can be checked to determine disease activity in the future.