Modern efforts toward explaining human disease purely based upon sequencing cannot possibly succeed in isolation,” says Andrew P. Feinberg, M.D., professor of medicine and director of the Center for Epigenetics at Johns Hopkins University School of Medicine. “At least half of human disease is caused by exposure to the environment.”
While the contribution of genetic factors to disease is more predictable and easier to study in the case of highly penetrant Mendelian disorders, most medical conditions involve multiple genes that may interact with one another and with environmental factors. Particularly for these conditions, capturing epigenetic changes becomes a crucial aspect of understanding pathogenesis and designing prophylactic and therapeutic interventions.
In a recent study, Dr. Feinberg and colleagues reported that large blocks of the human genome are hypomethylated in the epidermis as a result of sun exposure, which together with aging represents a known risk factor for skin cancer. These hypomethylated regions overlap with regions that have methylation changes in patients with squamous cell carcinoma.
Epigenetics Research Reveals a Range of Clinical Possibilities