Don't forget the 'epi' in genetics research, scientist says

April 5, 2018, Johns Hopkins University School of Medicine
A depiction of the double helical structure of DNA. Its four coding units (A, T, C, G) are color-coded in pink, orange, purple and yellow. Credit: NHGRI

In a review article published April 5 in the New England Journal of Medicine, scientist Andrew Feinberg, M.D., calls for more integration between two fields of DNA-based research: genetics and epigenetics.

Most people are familiar with genetics, a field of research that focuses on the precise sequence of chemicals that form the ladder-like structure of DNA. However, epigenetics is not as well known among the public. It's the study of how information is added onto or influences the read-out of genes and, Feinberg says, is not combined often enough with genetics research to understand human disease.

Feinberg, who directs the Center for Epigenetics in the Johns Hopkins Institute for Basic Biomedical Sciences, says that the field of epigenetics captures what happens to our genome after environmental exposures in a way that DNA sequencing by itself cannot.

"We tend to think of our genome as static, but it isn't. Most disease is influenced by some component of the changing environment and our variable exposure to it," says Feinberg, the King Fahd Professor of Medicine, Oncology, Molecular Biology and Genetics. "Looking at our genetic sequence alone doesn't tell us everything about that exposure."

One type of epigenetic change to the genome occurs when small chemical groups glom on to the ladder structure of DNA. Such chemical flags don't change the DNA code itself. Rather, they change how genes are turned on and off. Similarly, other epigenetic changes occur in how DNA and proteins are compacted in the nucleus of the cell. If they are packed tightly, DNA is less open to structures that "read" the chemical alphabet of genes and manufacture proteins.

Epigenetic changes have been found in the lungs of smokers and cord blood of infants prenatally exposed to smoke, writes Feinberg. He also points to epidemiologic studies showing an association between famine in Sweden, Germany and China and shortened lifespans and schizophrenia in subsequent generations, and studies in mice and humans of nutritional deficiencies that lead to disease, an indication that may occur early in life and can be heritable.

In addition, he says, the modern revolution in gene sequencing has revealed many mutations in cancers that control epigenetic factors.

Yet, he sees a wide array of diseases, including autoimmune disorders, diabetes and rheumatoid arthritis, that can benefit from integrating epigenetic and genetic research. "Epigenetics stands at the interface of the genome, development and environmental exposure," he writes.

He suggests that combining genomewide and epigenomewide association studies can overcome problems of assigning cause and effect to specific alterations among either type of study alone.

Feinberg also sees potential in combining and genetics to identify people at risk for disease and monitor a treatment's effectiveness.

He also says that scientists know comparatively little about how existing drugs may be altering patients' epigenomes. Such new discoveries, he says, will depend on collaborations between pharmacologists and computational and physical biologists.

Explore further: How randomness helps cancer cells thrive

More information: New England Journal of Medicine (2018). DOI: 10.1056/NEJMra1402513

Related Stories

How randomness helps cancer cells thrive

March 27, 2017
In a research effort that merged genetics, physics and information theory, a team at the schools of medicine and engineering at The Johns Hopkins University has added significantly to evidence that large regions of the human ...

Team finds new genetic and epigenetic contributors to diabetes

January 6, 2015
An analysis of the genomes and epigenomes of lean and obese mice and humans has turned up a wealth of clues about how genes and the environment conspire to trigger diabetes, Johns Hopkins researchers say. Their findings reveal ...

New tool pinpoints genetic sources of disease

March 20, 2014
Many diseases have their origins in either the genome or in reversible chemical changes to DNA known as the epigenome. Now, results of a new study from Johns Hopkins scientists show a connection between these two "maps." ...

Immune diseases inflict identical twins differently

December 13, 2017
Any parent with identical twins knows their two children are actually remarkably different. Identical twins are genetically identical, but they are not identical in gene expressions, a difference attributable to epigenetics. ...

Researchers investigate effect of environmental epigenetics on disease and evolution

August 3, 2015
Washington State University researchers say environmental factors are having an underappreciated effect on the course of disease and evolution by prompting genetic mutations through epigenetics, a process by which genes are ...

Recommended for you

Childhood stress leaves lasting mark on genes

July 18, 2018
Kids who experience severe stress are more likely to develop a host of physical and mental health problems by the time they reach adulthood, including anxiety, depression and mood disorders. But how does early life stress ...

Study shows DNA methylation related to liver disease among obese patients

July 18, 2018
DNA methylation is a molecular process that helps enable our bodies to repair themselves, fight infection, get rid of environmental toxins, and even to think. But sometimes this process goes awry.

Protein found to be key component in irregularly excited brain cells

July 17, 2018
In a new study in mice, researchers have identified a key protein involved in the irregular brain cell activity seen in autism spectrum disorders and epilepsy. The protein, p53, is well-known in cancer biology as a tumor ...

World's largest study on allergic rhinitis reveals new risk genes

July 17, 2018
An international team of scientists led by Helmholtz Zentrum München and University of Copenhagen has presented the largest study so far on allergic rhinitis in the journal Nature Genetics. The data of nearly 900,000 participants ...

New platform poised to be next generation of genetic medicines

July 16, 2018
A City of Hope scientist has discovered a gene-editing technology that could efficiently and accurately correct the genetic defects that underlie certain diseases, positioning the new tool as the basis for the next generation ...

Overcoming a major barrier to developing liquid biopsies

July 16, 2018
The idea of testing blood or urine to find markers that help diagnose or treat disease holds great promise. But as technology has improved to allow researchers to examine tiny fragments of RNA, one major problem has led to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.