DNA methylation represents an annotation system for marking the genetic text, thus providing instruction as to how and when to read the information and control transcription. Unlike sequence information, which is inherited, methylation patterns are established in a programmed process that continues throughout development, thus setting up stable gene expression profiles. This DNA methylation paradigm is a key player in medicine. Some changes in methylation closely correlate with age providing a marker for biological ageing, and these same sites could also play a part in cancer. The genome continues to undergo programmed variation in methylation after birth in response to environmental inputs, serving as a memory device that could affect ageing and predisposition to various metabolic, autoimmune, and neurological diseases. Taking advantage of tissue-specific differences, methylation can be used to detect cell death and thereby monitor many common diseases with a simple cell-free circulating-DNA blood test.
Bibliographical noteFunding Information:
The following research grants contributed to the evolution, organisation, and writing of this Review: Rosetrees Foundation, the Israel Cancer Research Fund, the Israel Science Foundation, the Smart Foundation, Lew Sanders, the Juvenile Diabetes Research Foundation, and the National Institute of Diabetes and Digestive and Kidney Diseases-supported Human Islet Research Network .
© 2018 Elsevier Ltd