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    Chromosome 18, Tetrasomy 18p

    Important
    It is possible that the main title of the report Chromosome 18, Tetrasomy 18p 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

    • Tetrasomy, Short Arm of Chromosome 18

    Disorder Subdivisions

    • None

    General Discussion

    Chromosome 18, Tetrasomy 18p is a very rare chromosomal disorder in which the short arm of the 18th chromosome (18p) appears four times (tetrasomy) rather than twice in cells of the body. Individuals with a normal chromosomal make-up (karyotype) have two 18th chromosomes, both of which have a short arm ("18p") and a long arm ("18q"). However, in individuals with Chromosome 18, Tetrasomy 18p, four short arms (18ps) are present in cells of the body rather than the normal two.

    The symptoms of Chromosome 18, Tetrasomy 18p may vary from case to case. Many affected individuals may have abnormalities of the head and facial (craniofacial) area; malformations of the spine, hands, and/or feet; neuromuscular abnormalities, such as increased muscle tone (hypertonia), increased reflex reactions (hyperreflexia), and difficulty coordinating movement; kidney (renal) malformations; and/or additional physical abnormalities. In addition, children and adults with Chromosome 18, Tetrasomy 18p often exhibit moderate to severe mental retardation, limitations in speech, and/or behavioral abnormalities. In most cases, Chromosome 18, Tetrasomy 18p is the result of a spontaneous (de novo) genetic change (mutation) early in embryonic development that occurs for unknown reasons (sporadic).

    Resources

    Children's Craniofacial Association
    13140 Coit Road
    Suite 517
    Dallas, TX 75240
    USA
    Tel: (214)570-9099
    Fax: (214)570-8811
    Tel: (800)535-3643
    Email: contactCCA@ccakids.com
    Internet: http://www.ccakids.com

    Support Organization for Trisomy 18, 13, and Related Disorders
    2982 S. Union Street
    Rochester, NY 14624-1926
    Fax: (585)594-1957
    Tel: (800)716-7638
    Email: barbv@trisomy.org
    Internet: http://www.trisomy.org

    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

    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

    AmeriFace
    P.O. Box 751112
    Limekiln, PA 19535
    USA
    Tel: (702)769-9264
    Fax: (702)341-5351
    Tel: (888)486-1209
    Email: info@ameriface.org
    Internet: http://www.ameriface.org

    Chromosome Disorder Outreach, Inc.
    P.O. Box 724
    Boca Raton, FL 33429-0724
    USA
    Tel: (561)395-4252
    Fax: (561)395-4252
    Email: info@chromodisorder.org
    Internet: http://www.chromodisorder.org/CDO/

    National Kidney Foundation
    30 East 33rd Street
    New York, NY 10016
    Tel: (212)889-2210
    Fax: (212)689-9261
    Tel: (800)622-9010
    Email: info@kidney.org
    Internet: http://www.kidney.org

    Chromosome 18 Registry & Research Society
    7155 Oakridge Drive
    San Antonio, TX 78229
    Tel: (210)657-4968
    Fax: (210)657-4968
    Email: office@chromosome18.org
    Internet: http://www.chromosome18.org

    NIH/National Kidney and Urologic Diseases Information Clearinghouse
    3 Information Way
    Bethesda, MD 20892-3580
    Fax: (703)738-4929
    Tel: (800)891-5390
    TDD: (866)569-1162
    Email: nkudic@info.niddk.nih.gov
    Internet: http://www.kidney.niddk.nih.gov/

    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

    Craniofacial Foundation of America
    975 East Third Street
    Chattanooga, TN 37403
    Tel: (423)778-9176
    Fax: (423)778-8172
    Tel: (800)418-3223
    Email: terry.smyth@erlanger.org
    Internet: http://www.craniofacialfoundation.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/

    Tetrasomy 18p Canada
    14 Deeth Drive, Unit A
    Weston
    Ontario, M9P 2J7
    Canada
    Tel: 4167687311
    Tel: 6478009889
    Email: Lorrine@tetrasomy18p.ca, Velvet@tetrasomy18p.ca
    Internet: http://www.tetrasomy18p.ca

    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: 4/10/2009
    Copyright 1996, 2001, 2009 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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