Title: trisomy 18
Long Title: IUPAC Gold Book - trisomy 18
DOI: 10.1351/goldbook.11324
Status: current

Definition
Presence of part or all of an extra chromosome 18 from nondisjunction during meiosis.

Note
This leads to multiple congenital abnormalities and mental retardation, and is usually fatal in early childhood.

Related Term
- congenital abnormalities: https://goldbook.iupac.org//terms/view/10554

Source
- PAC, 2016, 88, 713. 'Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)' on page 815 (https://doi.org/10.1515/pac-2015-1202)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/11324/html
- json: https://goldbook.iupac.org/terms/view/11324/json
- xml: https://goldbook.iupac.org/terms/view/11324/xml

Citation: Citation: 'trisomy 18' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.11324
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Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-07-14T21:24:47+00:00