Klinefelter Syndrome

Last updated: March 1, 2015

Note:  All links going to other websites will open in the same window. Use the Back button to return to our site.

  • American Association for Klinefelter Syndrome Information and Support (AAKSIS) is dedicated to bringing you accurate and current information about Klinefelter Syndrome and is a network for individuals, families, and anyone interesting in learning more about Klinefelter Syndrome. Klinefelter Syndrome, 47XXY, the most common of the sex chromosome variations, is said to occur in 1 out of 500 males. Statistics suggest that there are thousands of 47XXY individuals in the United States alone. Many remain undiagnosed.
  • Kleinfelter Syndrome from the Mayo Clinic. Klinefelter syndrome is a genetic condition that results when a boy is born with an extra copy of the X chromosome. Klinefelter syndrome is a common genetic condition affecting males.
  • What is Klinefelter syndrome? a service of the U.S. National Library of Medicine®
  • What are common symptoms of Klinefelter syndrome (KS)? a Guide for XXY males and their families from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH).
  • Klinefelter's Syndrome – also called: XXY male from MedlinePlus, the U.S. National Library of Medicine (NLM), U.S. Department of Health and Human Services (HHS), National Institutes of Health (NIH).