mutation
noun
mu·ta·tion
myü-ˈtā-shən 
1
: a significant and basic alteration : change
2
: umlaut
3
a
: a relatively permanent change in hereditary material that involves either a change in chromosome structure or number (as in translocation, deletion, duplication, or polyploidy) or a change in the nucleotide sequence of a gene's codons (as in frameshift or missense errors) and that occurs either in germ cells or in somatic cells but with only those in germ cells being capable of perpetuation by sexual reproduction
Mutations known to cause disease have been identified in approximately 1000 genes.—
Alan E. Guttmacher and Francis S. Collins
Alan E. Guttmacher and Francis S. Collins
also
: the process of producing a mutation
Microorganisms have been used extensively to study mutation … —George A. Wistreich et al.
George A. Wistreich et al.
b
: an individual, strain, or trait resulting from mutation
The worst E. coli bacterium, E. coli 0157:H, a mutation discovered in 1982 that has at least sixty-two subtypes, causes hemorrhagic colitis …—Wayne Biddle
Wayne Biddle
mutationally
adverb
Examples of mutation in a Sentence
The cat's short tail is the result of mutation.
The condition is caused by a genetic mutation.
The building is a mutation of the original design.
Recent Examples on the Web
For example, mutations in the CNTNAP2 gene, which plays a role in the development and function of the nervous system, have been linked to a predisposition of autism, particularly among some Amish children.
—Mary Kekatos, ABC News, 14 Oct. 2025
Blinky became a symbolic picture for real-world commentary regarding the dangers of mutation and nuclear waste, and in 2011, a real-life three-eyed wolf fish was caught near an Argentinian nuclear plant, per ZME Science.
—Zoe Kaplan, PEOPLE, 11 Oct. 2025
In addition, a specific mutation in the tau gene increases pTau217 levels.
—Robert Martone, Scientific American, 10 Oct. 2025
The disease, which typically emerges between 30 and 50 years of age, is caused by a mutation in the HTT gene, which triggers the cells to create a protein called huntingtin that can cause damage to the brain.
—Melissa Rudy, FOXNews.com, 8 Oct. 2025
See All Example Sentences for mutation
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Mary Kekatos, ABC News, 14 Oct. 2025
Blinky became a symbolic picture for real-world commentary regarding the dangers of mutation and nuclear waste, and in 2011, a real-life three-eyed wolf fish was caught near an Argentinian nuclear plant, per ZME Science.
—Zoe Kaplan, PEOPLE, 11 Oct. 2025
In addition, a specific mutation in the tau gene increases pTau217 levels.
—Robert Martone, Scientific American, 10 Oct. 2025
The disease, which typically emerges between 30 and 50 years of age, is caused by a mutation in the HTT gene, which triggers the cells to create a protein called huntingtin that can cause damage to the brain.
—Melissa Rudy, FOXNews.com, 8 Oct. 2025
See All Example Sentences for mutation
Cite this Entry
“Mutation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mutation. Accessed 20 Oct. 2025.
Copy CitationKids Definition
mutation
noun
mu·ta·tion
myü-ˈtā-shən
1
: a basic and important change
2
a
: a permanent change in hereditary material involving either a change in the position of the genes on the chromosomes or a basic change in the chemical structure of a gene
also
: the process of producing a mutation
b
: an individual, strain, or trait resulting from mutation
Medical Definition
mutation
noun
mu·ta·tion
myü-ˈtā-shən
1
: a relatively permanent change in hereditary material that involves either a change in chromosome structure or number (as in translocation, deletion, duplication, or polyploidy) or a change in the nucleotide sequence of a gene's codons (as in frameshift or missense errors) and occurs either in germ cells or in somatic cells but with only those in germ cells being capable of perpetuation by sexual reproduction
also
: the process of producing a mutation
2
: an individual, strain, or trait resulting from mutation
Love words? Need even more definitions?
Merriam-Webster unabridged
Share