Other Names for this Disease
- Klinefelter's syndrome
- XXY syndrome
What are the signs and symptoms of Klinefelter syndrome?
What causes Klinefelter syndrome?
Is Klinefelter syndrome inherited?
How might Klinefelter syndrome be treated?
The most common symptom of Klinefelter syndrome is infertility. Other symptoms may include:
- Small, firm testicles
- Small penis
- Only a small amount of body hair
- Sexual difficulties
- Enlarged breasts (gynecomastia)
- Tall height
- Abnormal body proportions (long legs, short trunk)
Boys with Klinefelter syndrome may also have learning disabilities and difficulty with speech and language development. They tend to be quiet, sensitive, and unassertive, but personality characteristics vary among males with this condition. 
Management options available to individuals with signs and symptoms of Klinefelter syndrome may include:
- Educational interventions – As children, many individuals with Klinefelter syndrome qualify for special services to help them in school. Teachers can also help by using certain methods in the classroom, such as breaking bigger tasks into small steps.
- Therapeutic options – A variety of therapists, such as physical, speech, occupational, behavioral, mental health, and family therapists, can often help reduce or eliminate some of the symptoms of Klinefelter syndrome such as poor muscle tone, speech and language problems, or low self-confidence.
- Medical management – About half of individuals with KS have low testosterone levels, which may be raised by taking supplemental testosterone. Having a more normal testosterone level can help individuals develop bigger muscles, a deeper voice, and facial and body hair. Many healthcare providers recommend testosterone therapy when a boy reaches puberty. However, not all males with KS benefit from testosterone therapy, and this therapy also may not be suitable for some individuals depending on gender identity. Some individuals may opt to have breast removal or reduction surgery.
- Aksglaede L, Link K, Giwercman A, Jørgensen N, Skakkebaek NE, Juul A. 47,XXY Klinefelter syndrome: clinical characteristics and age-specific recommendations for medical management. Am J Med Genet C Semin Med Genet. February 15, 2013; 163C(1):55-63.
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- Klinefelter Syndrome. National Institute of Child Health and Human Development (NICHD) . November 2012; http://www.nichd.nih.gov/health/topics/klinefelter/conditioninfo/Pages/Default.aspx. Accessed 8/21/2013.