DNA methylation

noun

: the enzymatically controlled addition of a methyl group to a nucleotide base (such as cytosine in eukaryotes) in a molecule of DNA that plays a role in regulating gene expression (as by the inhibition of genetic transcription)

When a methyl group attaches to a specific spot on a gene—a process called DNA methylation—it can change the gene's expression, turning it off or on, dampening it or making it louder.

—John Cloud

A handful of drugs that affect DNA methylation already exist, and are being used to treat cancers in which faulty gene labeling plays a role.

—Helen Pilcher

A process called DNA methylation sets down "marks" on bits of DNA and is typically thought to squelch gene expression.

—Sarah Baldauf

DNA methylation is a mark on genomic DNA made by addition of methyl groups to cytosine bases …

—Adrian Bird

Examples of DNA methylation in a Sentence

Recent Examples on the Web

One way to assess biological age is by focusing on a biological process known as DNA methylation, which involves molecular changes over time that turn different genes on and off. —Lisa Rapaport, EverydayHealth.com, 29 July 2024

The key biomarker was change in DNA methylation – the process by which a small molecule known as a methyl group is added to DNA or proteins, essentially inhibiting or triggering gene expression. —New Atlas, 28 July 2024

Between the two groups of animals, consistent variations in DNA methylation–a process where methyl groups bind to regions of the genome within a cell, and silence certain genes–are detectable. —Lauren Leffer, Popular Science, 28 Mar. 2024

The plan is to enroll 1,500 firefighters in the study who will donate blood or plasma for a year, monitoring for DNA methylation cancer biomarkers. —Patricia Kime, Hannah Norman, Kff Health News, Anchorage Daily News, 16 Sep. 2023

The study, published Wednesday in PLOS ONE, builds on an emerging body of research that links faster biological aging, measured by a process called DNA methylation (DNAm), to low socioeconomic status — a phrase that encompasses education, income, and wealth. —Ambar Castillo, STAT, 5 July 2023

Known as DNA methylation, this process adds molecules to DNA that can affect a person’s health risks. —Will Sullivan, Smithsonian Magazine, 8 May 2023

Using DNA methylation clocks to study biomarkers of aging, researchers measured changes in biological age in humans and mice in response to various stressful stimuli, including surgically attaching pairs of mice that were three months old and 20 months old. —L'oreal Thompson Payton, Fortune Well, 21 Apr. 2023

Like other epigenetic aging tests on the market, Tally Health looks at patterns in DNA methylation—the chemical tags on DNA code that affect the activity of genes. —Emily Mullin, WIRED, 2 Mar. 2023

Word History

First Known Use

1963, in the meaning defined above

Medical Definition

DNA methylation

noun

: the enzymatically controlled methylation of a nucleotide base (as cytosine in eukaryotes) in a molecule of DNA that plays a role in suppressing gene expression