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Diseases

Genetic and Rare Diseases Information Center (GARD)

Chromosome 20 trisomy


Other Names for this Disease
  • Trisomy chromosome 20
  • Trisomy 20
  • Trisomy 20 mosaicism
  • Mosaic trisomy 20
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Overview

Chromosome 20 trisomy, (also called trisomy 20) is a condition in which a fetus or individual has an extra full or partial copy of chromosome 20 in some or all of of his/her cells. An extra full copy of chromosome 20 in all of a person's cells is rare, and almost all fetuses with this do not survive past the first trimester of pregnancy.[1] The presence of an extra copy of only part of chromosome 20 is called partial trisomy 20; and an extra copy of chromosome 20 in only some of a person's cells is called mosaic trisomy 20. Mosaic trisomy 20 is the most common type of chromosome 20 trisomy and is one of the more common chromosomal abnormalities found during prenatal diagnostic testing. Studies have shown that the child is normal in the vast majority of prenatally diagnosed individuals. However, features that have been reported include spinal abnormalities (including spinal stenosis, vertebral fusion, and kyphosis), hypotonia (decreased muscle tone), lifelong constipation, sloped shoulders, and significant learning disabilities despite normal intelligence.[2] Trisomy 20 usually results from an error that occurs when an egg or sperm cell develops (before fertilization); mosaic trisomy 20 usually results from errors in cell division soon after fertilization.[3]
Last updated: 11/27/2015

References

  1. Mavromatidis G, Dinas K, Delkos D, Vosnakis C, Mamopoulos A, Rousso D. Case of prenatally diagnosed non-mosaic trisomy 20 with minor abnormalities. Journal of Obstetrics and Gynaecology Reearch. August 2010; 36(4):866-868. http://www.ncbi.nlm.nih.gov/pubmed/20666959. Accessed 11/27/2015.
  2. Willis MJ, Bird LM, Dell'Aquilla M, Jones MC. Expanding the phenotype of mosaic trisomy 20. American Journal of Medical Genetics. February 1, 2008; 146(3):330-336. http://www.ncbi.nlm.nih.gov/pubmed/18203170. Accessed 11/27/2015.
  3. Chromosome abnormalities. March of Dimes. February 2013; http://www.marchofdimes.com/Baby/birthdefects_chromosomal.html. Accessed 11/27/2015.
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Basic Information

In Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Chromosome 20 trisomy. Click on the link to view a sample search on this topic.
Other Names for this Disease
  • Trisomy chromosome 20
  • Trisomy 20
  • Trisomy 20 mosaicism
  • Mosaic trisomy 20
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.