Nonsynonymous

Part of speech: adjective

Definitions

1. A type of mutation or genetic change that alters the amino acid sequence of a protein, contrasting with changes that do not affect the resulting protein structure
2. A mutation that results in a different amino acid being incorporated into a protein, as opposed to changes that leave the original sequence unchanged
3. Referring to a genetic alteration that leads to the substitution of one amino acid for another, unlike mutations that do not modify the protein

Etymology: In molecular biology, "synonymous" has a precise meaning: two codons are synonymous if they code for the same amino acid. A nonsynonymous change is one that breaks that equivalence, swapping one amino acid for another in the resulting protein. The word is built from the prefix "non-", which goes back through Middle English "non" to Old English "nān", meaning "not one," and "synonymous," which combines Greek roots meaning "same name." The term is a modern technical coinage, formed by attaching "non-" to "synonymous." It belongs to the vocabulary of genetics and evolutionary biology, where researchers compare the rate of nonsynonymous changes with the rate of synonymous ones to judge whether natural selection has been acting on a gene.

Synonyms: different, distinct

Antonyms: synonymous, similar