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    XYY Syndrome

    Important
    It is possible that the main title of the report XYY 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

    • Jacob's syndrome
    • XYY karyotype
    • YY syndrome
    • 47, XYY syndrome

    Disorder Subdivisions

    • None

    General Discussion

    Summary
    XYY syndrome is a rare chromosomal disorder that affects males. It is caused by the presence of an extra Y chromosome. Males normally have one X and one Y chromosome. However, individuals with this syndrome have one X and two Y chromosomes. Affected individuals are usually very tall. Many experience severe acne during adolescence. Additional symptoms may include learning disabilities and behavioral problems such as impulsivity. Intelligence is usually in the normal range, although IQ is on average 10-15 points lower than siblings.

    Introduction
    In the past, there were many misconceptions about this disease. It was sometimes called the super-male disease because men with this syndrome were thought to be overly-aggressive and lacking in empathy. Recent studies have shown that this is not the case. Although individuals with XYY syndrome have an increased risk for learning disabilities and behavioral problems, they are not overly aggressive, nor are they at an increased risk of any serious mental illness. Because these boys are at a higher risk for having learning disabilities, they may benefit from speech therapy, tutoring, and general awareness of the specific issues they struggle with. Although the first years of school may be more challenging for boys with XYY syndrome, they generally go on to lead full, healthy, and normal lives.

    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

    National Mental Health Consumers' Self-Help Clearinghouse
    1211 Chestnut Street
    Suite 1207
    Philadelphia, PA 19107-6312
    USA
    Tel: (215)751-1810
    Fax: (215)636-6312
    Tel: (800)553-4539
    Email: info@mhselfhelp.org
    Internet: http://www.mhselfhelp.org

    Mental Health America
    2000 N. Beauregard Street, 6th Floor
    Alexandria, VA 22314-2971
    USA
    Tel: (703)684-7722
    Fax: (703)684-5968
    Tel: (800)969-6642
    TDD: (800)433-5959
    Email: infoctr@mentalhealthamerica.net
    Internet: http://www.mentalhealthamerica.net/

    National Alliance on Mental Illness
    3803 N. Fairfax Drive
    Suite 100
    Arlington, VA 22203-
    Tel: (703)524-7600
    Fax: (703)524-9094
    Tel: (800)999-6264
    TDD: (703)516-7227
    Email: membership@nami.org
    Internet: http://www.nami.org

    NIH/National Institute of Mental Health
    Health Science Writing, Press and Dissemination Branch
    6001 Executive Boulevard
    Room 8184, MSC 9663
    Bethesda, MD 20892-9663
    Tel: (301)443-4513
    Fax: (301)443-4279
    Tel: (866)615-6464
    TDD: (301)443-8431
    Email: nimhinfo@nih.gov
    Internet: http://www.nimh.nih.gov/index.shtml

    UNIQUE - Rare Chromosome Disorder Support Group
    P.O. Box 2189
    Caterham
    Surrey, CR3 5GN
    United Kingdom
    Tel: 4401883330766
    Fax: 4401883330766
    Email: info@rarechromo.org
    Internet: http://www.rarechromo.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/

    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: 10/3/2012
    Copyright 1990, 1992, 1998, 1999, 2002, 2012 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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