Skip to content

    Children's Health

    Font Size
    A
    A
    A

    Fragile X Syndrome

    Important
    It is possible that the main title of the report Fragile X 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

    • fragile site, folic acid type, rare, Fra(X)(Q27.3)
    • fragile X mental retardation protein, FMRP
    • fragile X mental retardation syndrome
    • marker X syndrome
    • Martin-Bell syndrome
    • mental retardation, X-linked, associated with Mar Xq28
    • X-linked mental retardation and macroorchidism

    Disorder Subdivisions

    • None

    General Discussion

    Fragile X syndrome is characterized by moderate intellectual disability in affected males and mild intellectual disability in affected females. Distinctive physical features are sometimes present in affected males including a large head, long face, prominent forehead and chin, protruding ears, loose joints and large testes, but these features develop over time and may not be obvious until puberty. Motor and language delays are usually present but also become more apparent over time. Behavioral abnormalities including autistic behaviors are common.

    Fragile X syndrome is caused by an abnormality (mutation) in the FMR1 gene. Affected individuals have an increased number of copies of a portion of the gene called CGG repeats. The greater the number of copies of CGG, the more likely there will be increased severity of the disorder. Fragile X syndrome occurs more often in males and results in more severe disease in males.

    Mutations in the FMR1 gene are associated with two other conditions in addition to the fragile X syndrome (FXTAS and POI) and these conditions have been termed FMR1-Related Disorders. (See the Related Disorders section of this report for brief summaries of the other disorders.)

    Resources

    The Arc
    1825 K Street NW, Suite 1200
    Washington, DC 20006
    Tel: (202)534-3700
    Fax: (202)534-3731
    Tel: (800)433-5255
    TDD: (817)277-0553
    Email: info@thearc.org
    Internet: http://www.thearc.org

    FRAXA Research Foundation
    10 Prince Place
    Newburyport, MA 01950
    USA
    Tel: (978)462-1866
    Fax: (978)463-9985
    Email: info@fraxa.org
    Internet: http://www.fraxa.org

    National Fragile X Foundation
    1615 Bonanza St
    Suite 202
    Walnut Creek, CA 94596
    USA
    Tel: (925)938-9300
    Fax: (925)938-9315
    Tel: (800)688-8765
    Email: natlfx@FragileX.org
    Internet: http://www.fragilex.org

    New York State Office for People with Developmental Disabilities
    44 Holland Avenue
    Albany, NY 12229
    Tel: (866)946-9733
    TDD: (866)933-4889
    Email: Commissioners.Correspondence.Unit@omr.state.ny.us
    Internet: http://www.omr.state.ny.us/ws/ws_ibr_resources.jsp

    NIH/National Institute on Aging
    31 Center Drive, MSC 2292
    Building 31
    Room 5C27
    Bethesda, MD 20892
    Tel: (301)496-1752
    Fax: (301)496-1072
    Tel: (800)222-2225
    TDD: (800)222-4225
    Email: bapquery@nia.nih.gov
    Internet: http://www.nih.gov/nia

    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/

    New Horizons Un-Limited, Inc.
    811 East Wisconsin Ave
    P.O. Box 510034
    Milwaukee, WI 53203
    USA
    Tel: (414)299-0124
    Fax: (414)347-1977
    Email: horizons@new-horizons.org
    Internet: http://www.new-horizons.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

    Let Them Hear Foundation
    1900 University Avenue, Suite 101
    East Palo Alto, CA 94303
    Tel: (650)462-3174
    Fax: (650)462-3144
    Email: info@letthemhear.org
    Internet: http://www.letthemhear.org

    Fragile X Society
    Road End House
    6 Stortford Road
    Great Dunmow
    Essex, CM6 1DA
    United Kingdom
    Tel: 004401371875100
    Email: info@fragilex.org.uk
    Internet: http://www.fragilex.org.uk

    Medical Home Portal
    Dept. of Pediatrics
    University of Utah
    P.O. Box 581289
    Salt Lake City, UT 84158
    Tel: (801)587-9978
    Fax: (801)581-3899
    Email: mindy.tueller@utah.edu
    Internet: http://www.medicalhomeportal.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: 8/25/2010
    Copyright 1988, 1989, 1990, 1991, 1994, 1995, 1997, 1998, 1999, 2006, 2010 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.

    Today on WebMD

    child with red rash on cheeks
    What’s that rash?
    plate of fruit and veggies
    How healthy is your child’s diet?
     
    smiling baby
    Treating diarrhea, fever and more.
    Middle school band practice
    Understanding your child’s changing body.
     

    worried kid
    fitArticle
    jennifer aniston
    Slideshow
     
    Measles virus
    Article
    sick child
    Slideshow
     

    babyapp
    New
    Child with adhd
    Slideshow
     
    rl with friends
    fitSlideshow
    Child Coughing or Sneezing into Elbow
    Article