Klinefelter's Syndrome

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

• Educational services
• Physical, speech and occupational therapy
• Medical treatments including testosterone replacement

National Institute of Child Health and Human Development

External Resources

Klinefelter Syndrome Support - Educational and support information about Klinefelter Syndrome/XXY and its variants.

Klinefelter Syndrome - Overview and medical information.

Klinefelter's Syndrome gynecomastia - Male chest recontouring for large male breasts (gynecomastia) found in Klinefelter's Syndrome with surgical reduction by excision and liposuction. Before and after photographs, links, movies, and patient question and answer boards.

Klinefelter Syndrome? - A parent's point of view, with articles.

Genetic Org Home - Information about Klinefelter Syndrome, when it was first discovered, the common characteristics, and treatment.

American Association for Klinefelter Syndrome Information and Support (AAKSIS) - Email list, conference, membership, newsletter, regional groups and resource links.

Turner Center - Literature on XYY, Klinefelter, XXX, and Turner's Syndrome.

XXY Information (Klinefelter Syndrome) - Medical information, news, and links.

My Klinefelter's Syndrome Page - David Brager's story, with information about Klinefelter's.

drkoop.com: Klinefelter Syndrome - A chromosome abnormality that affects only men and causes hypogonadism.

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