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47 XXX syndrome

Other Names for this Disease
  • Triple X syndrome
  • Triple-X chromosome syndrome
  • Triple-X female
  • Triplo X syndrome
  • Trisomy X
More Names
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47 XXX syndrome, also called trisomy X, is characterized by the presence of an additional (third) X chromosome in each of a female's cells (which normally have two X chromosomes). An extra copy of the X chromosome is associated with tall stature, learning problems, and other features in some girls and women. Seizures or kidney abnormalities occur in about 10 percent of affected females. It is usually caused by a random event during the formation of reproductive cells (eggs and sperm); an error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes. Treatment typically focuses on individual signs and symptoms that a person may have. Some females with trisomy X have an extra X chromosome in only some of their cells; this is called 46,XX/47,XXX mosaicism.[1]
Last updated: 1/8/2011


  1. Triple X syndrome. Genetics Home Reference. January 2009; Accessed 1/8/2011.
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Basic Information

  • Genetics Home Reference (GHR) contains information on 47 XXX syndrome. This website is maintained by the National Library of Medicine.
  • The National Organization for Rare Disorders (NORD) is a federation of more than 130 nonprofit voluntary health organizations serving people with rare disorders. Click on the link to view information on this topic.
  • Unique is a source of information and support to families and individuals affected by rare chromosome disorders.

In Depth Information

  • Orphanet is a European reference portal for information on rare diseases and orphan drugs.  Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss 47 XXX syndrome. Click on the link to view a sample search on this topic.