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Created date

August 23rd, 2010
Two identical twins remain healthy their whole lives and then, at age 75, one develops Alzheimer s disease. Genetics can t account for this the pair has the exact same DNA. Then what is the difference? Enter the epigenome, which sits atop DNA and can silence or activate a gene, directing it to behave a certain way.

The missing link

At the fore of researching this phenomenon which scientists have called the missing link between genetics, disease, and the environment is the Johns Hopkins Center for Epigenetics. There, scientists have discovered that as people age, the variation in gene expression becomes more prevalent, with the epigenome dictating various messages to the DNA. For example, diet and lifestyle choices can impact whether or not certain genes (e.g., cancer) get turned on or are silenced. Currently, Johns Hopkins researchers are investigating epigenetic markers to predict and treat various conditions that have, until now, challenged the medical community. For example, a team at Johns Hopkins has used epigenetics to predict colorectal cancer, which, according to the American Cancer Society, goes undetected approximately 60% of the time. There has been no treatment proven to increase odds of survival for late-stage colorectal cancer patients, who typically live between four to six months after diagnosis. At present, Johns Hopkins researchers are in the midst of a trial using a combination of epigenetic and other therapies to treat people whose cancer has advanced. Another Johns Hopkins lab has discovered an epigenetic therapy for those who develop recurrent lung cancer after surgery. In addition, researchers at the Center for Epigenetics are working to predict and treat Alzheimer s disease, frailty, and mental disorders, among other conditions. It s heartening, says Andrew Feinberg, M.D., M.P.H., professor of molecular medicine and director of the Center for Epigenetics. We re reinventing science as we go.