Early predictors of asthma and allergy in children: The role of epigenetics

Purpose of review Asthma and allergic diseases are among the most prevalent chronic noncommunicable diseases of childhood. Although epidemiologic studies suggest that asthma begins in the preschool years, the lack of firm diagnostic criteria to distinguish children who will wheeze only transiently during early-life lower respiratory illnesses from children who will wheeze persistently and develop asthma prevents pinpointing the time at which disease truly begins. Epigenetic mechanisms link gene regulation to environmental cues and developmental trajectories. This article reviews, the search for epigenetic predictors of asthma and/or allergy that can be identified already at birth and/or in early life. Recent findings DNA methylation signatures associated with asthma and/or allergy at birth, and time-dependent DNA methylation signatures associated with allergic disease phenotypes in early life have been identified. Summary The identification of early epigenetic predictors of allergic diseases points to a potential role of epigenetic mechanisms in regulating the inception of and the susceptibility to these diseases. Predictive signatures to more accurately estimate a child's risk for asthma and allergy may improve childhood asthma diagnosis. Moreover, understanding the biological implications of these signatures may help elucidate novel disease pathways and endotypes.