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
John CloudA 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
Helen PilcherA process called DNA methylation sets down "marks" on bits of DNA and is typically thought to squelch gene expression.—Sarah Baldauf
Sarah BaldaufDNA methylation is a mark on genomic DNA made by addition of methyl groups to cytosine bases …—Adrian Bird
Adrian BirdExamples of DNA methylation in a Sentence
Recent Examples on the Web
The researchers measured biological aging by assessing DNA methylation in saliva samples, which is a good indicator of exposure to chronic stress.
—Catherine Ho, San Francisco Chronicle, 11 Mar. 2026
Epigenetic clocks analyze small chemical tags on DNA known as DNA methylation.
—Tom Gavin, EverydayHealth.com, 9 Mar. 2026
Instead of cutting or permanently altering DNA, STX-1150 essentially installs modifications and DNA methylation marks at the PCSK9 locus in liver cells, which silences gene expression in a way that can be reversed if needed.
—New Atlas, 25 Jan. 2026
In fact, our team is currently examining how DNA methylation patterns across all genes affect long-term outcomes in children with traumatic brain injury.
—Amery Treble-Barna, The Conversation, 9 Dec. 2025
However, scientists are developing tools that more precisely predict life expectancy based upon empirical indicators, such as mutation rates, blood biomarkers, telomere length and DNA methylation patterns that measure how your body is aging at a cellular level.
—David A. Brenner, San Diego Union-Tribune, 24 July 2025
Using a novel approach that combines AI with individualized DNA methylation analysis, the test achieved 98.6 percent specificity.
—Alexis Kayser, MSNBC Newsweek, 1 May 2025
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Catherine Ho, San Francisco Chronicle, 11 Mar. 2026
Epigenetic clocks analyze small chemical tags on DNA known as DNA methylation.
—Tom Gavin, EverydayHealth.com, 9 Mar. 2026
Instead of cutting or permanently altering DNA, STX-1150 essentially installs modifications and DNA methylation marks at the PCSK9 locus in liver cells, which silences gene expression in a way that can be reversed if needed.
—New Atlas, 25 Jan. 2026
In fact, our team is currently examining how DNA methylation patterns across all genes affect long-term outcomes in children with traumatic brain injury.
—Amery Treble-Barna, The Conversation, 9 Dec. 2025
However, scientists are developing tools that more precisely predict life expectancy based upon empirical indicators, such as mutation rates, blood biomarkers, telomere length and DNA methylation patterns that measure how your body is aging at a cellular level.
—David A. Brenner, San Diego Union-Tribune, 24 July 2025
Using a novel approach that combines AI with individualized DNA methylation analysis, the test achieved 98.6 percent specificity.
—Alexis Kayser, MSNBC Newsweek, 1 May 2025
Cite this Entry
“DNA methylation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/DNA%20methylation. Accessed 2 Apr. 2026.
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