Opportunities for Studying Environmental Exposures using Epigenetics: The Importance of Methylome-wide Association Studies

Recent advances in high-throughput technology now allows measurement of the DNA methylome. Dr. Yan Sun, HERCULES investigator and year one pilot award recipient, discusses the value of methylome-wide association studies to look at connections of genes, environment and human diseases. In a recent paper “The Influences of Genetic and Environmental Factors on Methylome-Wide Association Studies for Human Diseases”, Dr. Sun reviews the state of current research studies addressing genetic determinants and environmental modifiers of DNA methylation (DNAm).


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His discussion of genetic determinants of the methylome describes the state of the science and the complementary work that has been conducted looking at environmental modifiers of DNAm. Highlighting arguably the most well-studied environmental factor (smoking), he describes the incredible opportunity to use DNAm sites as potential novel biomarkers for short and long-term exposures and for the identification of new epigenetic predictors of disease outcomes. Given the highly transient nature of many exposures, epigenetics offers a window into the past. Dr. Sun discusses the value of epigenetics in health research,

The epigenetic plasticity, in combination with life-course exposure of disease risks, will offer a new window in to a more comprehensive explanation for the development of chronic disease and inter-individual variation.

In terms of future research opportunities, monozygotic twin study designs are highly informative for studying epigenomic variation, particularly in regards to the environment. They control for unmeasured confounders like shared environmental influences during twin upbringing. Furthermore, in monozygotic discordant twin studies (where there are differences in disease outcomes among twins), it allows the study of within twin DNAm differences as they are associated with measured health traits altered by unshared environmental factors. In terms of exposome research, Dr. Sun’s review offers perspective on both the types of studies and techniques available and the areas of research needed in order to identify environmental exposures of health significance through an epigenetics approach.

Read about Dr. Sun’s pilot award here.