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    Klinefelter Syndrome

    Important
    It is possible that the main title of the report Klinefelter Syndrome is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

    Synonyms

    • KS
    • XXY male
    • XX male
    • XXYY male
    • XXXY male
    • XXXXY male

    Disorder Subdivisions

    • None

    General Discussion

    Klinefelter syndrome is a group of chromosomal disorders in males in which one or more extra X chromosomes are present. Males with the classic form of the disorder have one extra X chromosome. Males with variant forms of Klinefelter syndrome have additional X and/or Y chromosomes. The extra X and/or Y chromosome can affect physical, developmental, behavioral, and cognitive functioning. Common physical features may include tall stature, lack of secondary pubertal development, small testes (hypogonadism), delayed pubertal development, and breast development (gynecomastia) in late puberty. These features may be associated with low testosterone level and elevated gonadotropin levels.

    Resources

    March of Dimes Birth Defects Foundation
    1275 Mamaroneck Avenue
    White Plains, NY 10605
    Tel: (914)997-4488
    Fax: (914)997-4763
    Tel: (888)663-4637
    Email: Askus@marchofdimes.com
    Internet: http://www.marchofdimes.com

    49 XXXXY
    870 Miranda Green
    Palo Alto, CA 94306
    USA
    Tel: (360)892-7547
    Email: epwatzka@gmail.com
    Internet: http://www.xxxxysyndrome.com/index.htm

    Klinefelter Syndrome Association of Canada
    42 Ritson Road South, Upper floor,
    Oshawa
    Ontario, L1H 5G9
    Canada
    Tel: 9059262942
    Email: dj.rabinovitch@gmail.com

    NIH/National Institute of Child Health and Human Development
    31 Center Dr
    Building 31, Room 2A32
    MSC2425
    Bethesda, MD 20892
    Fax: (866)760-5947
    Tel: (800)370-2943
    TDD: (888)320-6942
    Email: NICHDInformationResourceCenter@mail.nih.gov
    Internet: http://www.nichd.nih.gov/

    American Association for Klinefelter Syndrome Information and Support
    c/o Roberta Rappaport
    3796 Ogden Ln.
    Mundelein, IL 60060-6038
    USA
    Tel: (888)466-5747
    Email: KSinfo@aaksis.org
    Internet: http://www.aaksis.org

    Klinefelters Syndrome Support Group of Australia
    Kellyville
    New South Wales, 2155
    Australia
    Tel: 04 25240773
    Email: YATESBECKS@bigpond.com

    XXYY Project
    PO Box 2172
    Littleton, CO 80161-2172
    USA
    Tel: (215)394-5942
    Email: inquiry@xxyysyndrome.org
    Internet: http://xxyysyndrome.org

    Genetic and Rare Diseases (GARD) Information Center
    PO Box 8126
    Gaithersburg, MD 20898-8126
    Tel: (301)251-4925
    Fax: (301)251-4911
    Tel: (888)205-2311
    TDD: (888)205-3223
    Internet: http://rarediseases.info.nih.gov/GARD/

    Madisons Foundation
    PO Box 241956
    Los Angeles, CA 90024
    Tel: (310)264-0826
    Fax: (310)264-4766
    Email: getinfo@madisonsfoundation.org
    Internet: http://www.madisonsfoundation.org

    Klinefelter Syndrome & Associates
    P.O. Box 872
    Pine, CO 80470-0872
    Tel: (303)400-9040
    Fax: (303)838-0753
    Tel: (888)999-9428
    Email: info@genetic.org
    Internet: http://www.genetic.org

    Focus Foundation, Inc.
    PO Box 190
    Davidsonville, MD 21035
    Tel: (443)223-7323
    Fax: (410)798-4801
    Email: info@thefocusfoundation.org
    Internet: http://www.thefocusfoundation.org

    For a Complete Report:

    This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

    The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

    It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

    This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

    For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email orphan@rarediseases.org

    Last Updated: 6/13/2011
    Copyright 1986, 1990, 1993, 1998, 1999, 2007, 2008, 2011 National Organization for Rare Disorders, Inc.

    WebMD Medical Reference from the National Organization for Rare Disorders

    Last Updated: May 28, 2015
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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