Published Online: March 12, 2015
Asthma is caused by inherited factors and environmental exposures. To date, genetic factors explain less than 10% of the risk of developing asthma, and although many environmental exposures are associated with asthma, it remains unclear why some individuals develop asthma when exposed to asthma-inducing environmental agents and others remain healthy. Now, in a study recently published study in The Journal of Allergy and Clinical Immunology (JACI), D.A. Schwartz and colleagues present the first results of a study that suggests that epigenetic marks may affect the risk of developing allergies and asthma.
Epigenetic marks are chemicals that bind to DNA that affect the expression of specific genes. These epigenetic marks can be both altered by the environment and can be inherited. Consequently, these epigenetic marks can potentially explain both the association of asthma with environmental exposures and familial inheritance. To study this, the authors of this study focused on a specific epigenetic mark, DNA methylation patterns, in peripheral blood immune cells of inner city children with persistent atopic asthma and healthy controls.
Comparing asthma subjects (N=97) to controls (N=97), the authors found that DNA methylation patterns were associated with allergic asthma in African American inner-city children and that these differences were seen in genes that alter the immune state. They also found that the asthma-associated DNA methylation changes were directly related to changes in gene expression, indicating that these DNA methylation changes are likely to be associated with the development of asthma. These findings were validated in a completely independent population of African American children with asthma.
The results of this study demonstrate that the epigenome is dysregulated in children with asthma. This observation provides a provocative new direction for this disease that might have important mechanistic, therapeutic, and public health implications.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.