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Klinefelter's Syndrome

URL of this page: http://www.nlm.nih.gov/medlineplus/klinefelterssyndrome.html

Also called: Also called: XXY male

Klinefelter's syndrome is a condition that occurs in men who have an extra X chromosome in most of their cells. The syndrome can affect different stages of physical, language and social development. The most common symptom is infertility. Because they often don't make as much of the male hormone testosterone as other boys, teenagers with Klinefelter's syndrome may have less facial and body hair and may be less muscular than other boys. They may have trouble using language to express themselves. They may be shy and have trouble fitting in.

It is important to start treatment as early as possible. With treatment, most boys grow up to have normal sex lives, successful careers and normal social relationships. Treatments include

National Institute of Child Health and Human Development

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The primary NIH organization for research on Klinefelter's Syndrome is the National Institute of Child Health and Human Development - http://www.nichd.nih.gov/

Date last updated: July 21 2008
Topic last reviewed: June 10 2008