Chromosome 18, Tetrasomy 18p

National Organization for Rare Disorders, Inc.

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.

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