11325 IUPAC Gold Book - trisomy 21 10.1351/goldbook.11325 11325 current synonym: Down syndrome 1 Presence of an extra chromosome 21. This produces a characteristic constellation of physical abnormalities with delayed growth and mental development, but is compatible with life into adulthood. The formerly used terms mongoloid and mongolism are now considered offensive. adulthood https://goldbook.iupac.org/terms/view/10348 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) https://goldbook.iupac.org/terms/view/11325/html https://goldbook.iupac.org/terms/view/11325/json https://goldbook.iupac.org/terms/view/11325/plain Citation: 'trisomy 21' 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.11325 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . 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. 2026-06-13T19:46:14+00:00