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

also : the process of producing a mutation

Microorganisms have been used extensively to study mutation …

—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

mutational

myü-ˈtā-sh(ə-)nəl 

adjective

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

The paper described research on the feasibility of using gene-editing to correct the mutation the caused their daughter’s disorder but did not mention a human trial nor their daughter’s death. — Simone McCarthy, CNN Money, 31 July 2026

The study argues that mutations in the DLL3 protein, which is vital during early body development, could be the root of short spine syndrome. — Greta Cross, USA Today, 31 July 2026

Until now, the most common mutation in pancreatic cancer tumors was considered untreatable. — Lisa Hughes, CBS News, 30 July 2026

Paul releases some of Fauci’s diary Paul in his opening statement sought to build the case that Fauci helped produce the COVID-19 pandemic by approving funding of research on virus mutations and then covered up his complicity. — Lauran Neergaard, Los Angeles Times, 29 July 2026

Word History

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing mutation

• back mutation
• gene mutation
• genetic mutation
• point mutation

Rhymes for mutation

• ablation
• aeration
• bination
• carnation
• cassation
• castration
• causation
• centration
• cessation
• cetacean
• chelation
• citation

Kids 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

mutational

-shnəl, -shən-ᵊl 

adjective

mutationally

-ē 

adverb