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Diseases

Genetic and Rare Diseases Information Center (GARD)

Klinefelter syndrome


Other Names for this Disease
  • Klinefelter's syndrome
  • XXY syndrome
Related Diseases
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Overview

Klinefelter syndrome (KS) is a condition that occurs in males when they have an extra X chromosome. Some males with KS have no obvious signs or symptoms while others may have varying degrees of cognitive, social, behavioral, and learning difficulties. Adults with Klinefelter syndrome may also experience primary hypogonadism (decreased testosterone production), small testes, enlarged breast tissue (gynecomastia), tall stature, and/or infertility. KS is not inherited, but usually occurs as a random event during the formation of reproductive cells (eggs and sperm). Treatment is based on the signs and symptoms present in each person.[1][2][3]
Last updated: 10/13/2015

References

  1. Klinefelter syndrome. Eunice Kennedy Shriver National Institute of Child Health and Human Development. November 2013; http://www.nichd.nih.gov/health/topics/klinefelter/Pages/default.aspx.
  2. Klinefelter syndrome. Genetics Home Reference. January 2013; http://ghr.nlm.nih.gov/condition=klinefeltersyndrome.
  3. Kirmse B. Klinefelter syndrome. MedlinePlus. November 2014; http://www.nlm.nih.gov/medlineplus/ency/article/000382.htm.
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Basic Information

  • The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) provides information related to the health of children, adults, and families. Click on the link to view information on this topic. 
  • Genetics Home Reference (GHR) contains information on Klinefelter syndrome. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The National Human Genome Research Institute's (NHGRI) mission encompasses a broad range of studies aimed at understanding the structure and function of the human genome and its role in health and disease. Click on the link to view the information page on this topic.
  • 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.

In Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • MeSH® (Medical Subject Headings) is a terminology tool used by the National Library of Medicine. Click on the link to view information on this topic.
  • 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 Klinefelter syndrome. Click on the link to view a sample search on this topic.
Other Names for this Disease
  • Klinefelter's syndrome
  • XXY syndrome
Related Diseases
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.