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Klinefelter Syndrome

Authors:
  • Cynthia M. Johnson, MA
Publication Type:

Condition

Klinefelter Syndrome

(47 XXY Syndrome; KS)

Definition

Klinefelter syndrome (KS) happens in males who have more than one X chromosome (XXY).

Causes

Males usually have a single X chromosome from their mother and a single Y one from their father. Males with KS get at least one extra X from either parent.

Risk Factors

There are no known risk factors for KS.

Symptoms

Symptoms may not be found until puberty or later.

Children may have problems with:

  • Speech
  • Learning
  • Behavior

Teens may have:

  • Delayed puberty
  • Enlarged breasts

Adults may have:

  • Small, firm testes
  • A poor sex drive or sexual problems
  • Infertility
  • Lack of facial and body hair
  • Breast pain
  • Hot flashes, sweating
  • A small penis (rare)

Diagnosis

The doctor will ask about symptoms and past health. A physical exam will be done.

KS is diagnosed with a genetic test. Blood tests may also be done.

Treatment

There is no cure. The goal is to manage symptoms. Options are:

  • Testosterone therapy to raise low levels of this hormone
  • Speech and language therapy
  • Special education services
  • Mental health counseling

Prevention

There are no known guidelines to prevent KS.

RESOURCES:

CANADIAN RESOURCES:

CANADIAN RESOURCES:

References

  • Klinefelter syndrome. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/klinefelter-syndrome.
  • Klinefelter syndrome (KS). National Institute of Child Health and Human Development website. Available at: https://www.nichd.nih.gov/health/topics/klinefelter.

Contributors

  • Kari Kuenn, MD
Last Updated:
2022-09-01

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This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.