mutation

American  

[myoo-tey-shuhn] / myuˈteɪ ʃən /

noun

1. Biology.

   1. Also called break.  a sudden departure from the parent type in one or more heritable characteristics, caused by a change in a gene or a chromosome.

   2. Also called sport.  an individual, species, or the like, resulting from such a departure.

2. the act or process of changing.

3. a change or alteration, as in form or nature.

4. Phonetics. umlaut.

5. Linguistics. (in Celtic languages) syntactically determined morphophonemic phenomena that affect initial sounds of words.

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mutation British  

/ mjuːˈteɪʃən /

noun

1. the act or process of mutating; change; alteration

2. a change or alteration

3. a change in the chromosomes or genes of a cell. When this change occurs in the gametes the structure and development of the resultant offspring may be affected See also inversion

4. another word for mutant

5. a physical characteristic of an individual resulting from this type of chromosomal change

6. phonetics

   1. (in Germanic languages) another name for umlaut

   2. (in Celtic languages) a phonetic change in certain initial consonants caused by a preceding word

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mutation Scientific  

/ myo̅o̅-tā′shən /

1. A change in the structure of the genes or chromosomes of an organism. Mutations occurring in the reproductive cells, such as an egg or sperm, can be passed from one generation to the next. Most mutations occur in junk DNA and have no discernible effects on the survivability of an organism. Of the remaining mutations, the majority have harmful effects, while a minority can increase an organism's ability to survive. A mutation that benefits a species may evolve by means of natural selection into a trait shared by some or all members of the species.

2. See Note at sickle cell anemia

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Other Word Forms

Derived Forms

• nonmutationally
  adverb
• mutational
  adjective
• mutationally
  adverb
• nonmutational
  adjective
• unmutational
  adjective

Etymology

Origin of mutation

First recorded in 1325–75; Middle English mutacio(u)n, from Latin mūtātion- (stem of mūtātiō ) “a changing”; see mutate, -ion

Explanation

A mutation is a genetic change that causes new and different characteristics, like the mutation on the dog's DNA that makes its tail shorter than its ancestors' tails. Mutation comes from the Latin word mutationem meaning "a changing." You might recognize this root in related words like mutate, mutable, and mutant. We often think of mutations as changes in an animal's genetic structure, but there are other kinds of mutations. For example, if an architect designs an award-winning building, her later designs that are similar might be called mutations of that one.

Example Sentences

Schiffman, 29, knew her mom had a prophylactic double mastectomy in 2015 after discovering she had the BRCA1 gene mutation.

From The Wall Street Journal • Jun. 7, 2026

The RAS G12 mutation accounts for most pancreatic cancers, but the study also showed that same high rate of survival for those without that specific mutation.

From MarketWatch • Jun. 1, 2026

A genetic test is needed which looks for a mutation of the BRCA2 genes.

From BBC • May 28, 2026

If that were true, scientists would not need to target every mutation separately.

From Science Daily • May 21, 2026

One woman with the BRCA1 mutation might develop an aggressive, metastatic variant of breast cancer at age thirty.

From "The Gene" by Siddhartha Mukherjee

Related Words

• alteration
• anomaly
• variation