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Missense mutation

In genetics, a missense mutation (a type of nonsynonymous mutation) is a point mutation in which a single nucleotide is changed, resulting in a codon that codes for a different amino acid^[1] (mutations that change an amino acid to a stop codon are considered nonsense mutations, rather than missense mutations).^[2] This can render the resulting protein nonfunctional. Such mutations are responsible for diseases such as Epidermolysis bullosa, sickle-cell disease, and SOD1 mediated ALS (Boillée 2006, p. 39).

For example, in the most common variant of sickle-cell disease, the 20th nucleotide of the gene for the beta chain of hemoglobin found on chromosome 11 is erroneously changed from the codon GAG (for glutamic acid) to GUG (which codes valine), so the 6th amino acid is incorrectly substituted (after the initial methionine amino acid is removed). ^[3]

Not all missense mutations lead to appreciable protein changes. An amino acid may be replaced by an amino acid of very similar chemical properties, in which case, the protein may still function normally; this is termed a neutral, "quiet", or conservative mutation. Alternatively, the amino acid substitution could occur in a region of the protein which does not significantly affect the protein secondary structure or function. When an amino acid may be encoded by more than one codon (so-called "degenerate coding") a mutation in a codon may not produce any change in translation; this would be a synonymous mutation (a form of silent mutation) and not a missense mutation.

References

^ MedTerms™ Medical Dictionary http://www.medterms.com/script/main/art.asp?articlekey=4396
^ First Aid for the USMLE Step 1, 2011
^ OMIM 141900.0243

missense mutation — [mis′sens΄] n. Genetics a type of mutation to a specific protein, that results from the substitution, during translation, of one amino acid for another * * * … Universalium
missense mutation — [mis′sens΄] n. Genetics a type of mutation to a specific protein, that results from the substitution, during translation, of one amino acid for another … English World dictionary
missense mutation — missense mutation. См. миссенс мутация. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) … Молекулярная биология и генетика. Толковый словарь.
Missense mutation — A genetic change involving the substitution of one base in the DNA for another which results in the substitution of one amino acid in a polypeptide for another. A missense mutation is a readable genetic message although its sense (its meaning) is … Medical dictionary
missense mutation — klaidžioji mutacija statusas T sritis augalininkystė apibrėžtis Neteisinga mutacija, kuriai vykstant viena nukleotidų pora kodone pakeičia kitą ir dėl to koduojama kita aminorūgštis. atitikmenys: angl. missense mutation rus. миссенс мутация … Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas
missense mutation — Gene mutation in which one amino acid is changed; the altered proteins may show some activity … Dictionary of invertebrate zoology
missense mutation — A mutation that alters a codon for a particular amino acid to one specifying a different amino acid … Dictionary of molecular biology
missense mutation — noun A point mutation that results in the substitution of one amino acid by another … Wiktionary
missense mutation — A mutation that changes a codon for one amino acid into a codon specifying another amino acid … Glossary of Biotechnology
missense mutation — A single base substitution in DNA that changes a codon for one amino acid into a codon for another … Dictionary of microbiology

Missense mutation

References

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