World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0027391852
Reproduction Date:

Title: Xxxxx  
Author: World Heritage Encyclopedia
Language: English
Subject: Aneuploidy
Publisher: World Heritage Encyclopedia


Classification and external resources
ICD-10 DiseasesDB 32625

XXXXX syndrome (also called pentasomy X or 49,XXXXX) is the presence of three additional X chromosomes. Diagnosis is done by karyotyping. Approximately 25 females have been described in medical literature worldwide with this extremely rare condition. The condition was first described in 1963. XXXXX syndrome is a type of aneuploidy (an abnormal number of chromosomes).


Physical traits

XXXXX syndrome is associated with microcephaly (undersized head), micrognathia (undersized jaw), and round face. The ears are generally low-set and malformed. Eyes are upslanting and show palpebral fissures, hypertelorism, and strabismus. Usually the nose is shaped with a broad and depressed nasal bridge and epicanthus, with the mouth having a cleft and highly arched palate, dental abnormalities, and thick, furrowed, and everted lips. The neck is webbed, much like the neck of a woman with Turner's syndrome. The hands and feet are small with overlapping toes, camptodactyly, clinodactyly, talipes equinovarus, and metatarsus varus. Scoliosis generally affects the spine and hypotonia affects the muscles.

Internal organs

The heart is usually affected by patent ductus arteriosus, atrial septal defect, ventricular septal defect, and aortic dextroposition. There is abnormal lobulation of the lungs and neonatal asphyxia. The ovaries are abnormally shaped with a small uterus and kidney hypoplasia.

Growth and development

XXXXX syndrome causes mental, growth, and motor retardation. There is occasional delayed puberty. Behavior and performance is affected by opisthotonoid posture. Recent observations have indicated an average of a 10 to 15 IQ point decrease for each extra X chromosome. Thus, the average IQ of XXXXX individuals tends to be between 55 and 70.[1]


See also


External links

  • Tetrasomy & Pentasomy X Syndrome Information and Support
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.