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Trisomy 18 Syndrome

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report Trisomy 18 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

  • Chromosome 18, Trisomy 18 Complete
  • Complete Trisomy 18 Syndrome
  • Edward's Syndrome
  • Trisomy E Syndrome

Disorder Subdivisions

  • None

General Discussion

Trisomy 18 syndrome is a rare chromosomal disorder in which all or a critical region of chromosome 18 appears three times (trisomy) rather than twice in cells of the body. In some cases, the chromosomal abnormality may be present in only a percentage of cells, whereas other cells contain the normal chromosomal pair (mosaicism).



Depending on the specific location of the duplicated (trisomic) portion of chromosome 18--as well as the percentage of cells containing the abnormality--symptoms and findings may be extremely variable from case to case. However, in many affected infants, such abnormalities may include growth deficiency, feeding and breathing difficulties, developmental delays, mental retardation, and, in affected males, undescended testes (cryptorchidism). Individuals with trisomy 18 syndrome may also have distinctive malformations of the head and facial (craniofacial) area, such as a prominent back portion of the head; low-set, malformed ears; an abnormally small jaw (micrognathia); a small mouth with an unusually narrow roof (palate); and an upturned nose. Affected infants may also have narrow eyelid folds (palpebral fissures), widely spaced eyes (ocular hypertelorism), and drooping of the upper eyelids (ptosis). Malformations of the hands and feet are also often present, including overlapped, flexed fingers; webbing of the second and third toes; and a deformity in which the heels are turned inward and the soles are flexed (clubfeet [talipes equinovarus]). Infants with trisomy 18 syndrome may also have a small pelvis with limited movements of the hips, a short breastbone (sternum), kidney malformations, and structural heart (cardiac) defects at birth (congenital). Such cardiac defects may include an abnormal opening in the partition dividing the lower chambers of the heart (ventricular septal defect) or persistence of the fetal opening between the two major arteries (aorta, pulmonary artery) emerging from the heart (patent ductus arteriosus). Congenital heart defects and respiratory difficulties may lead to potentially life-threatening complications during infancy or childhood.

Resources

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



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



Support Organization for Trisomy 13/18 and Related Disorders, UK

c/o Christine Rose

48 Froggatts Ride

Walmley

Sutton Coldfield

West Midlands, B76 2TQ SOFT

United Kingdom

Tel: 01213513122

Email: enquiries@soft.org.uk

Internet: http://www.soft.org.uk



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



Birth Defect Research for Children, Inc.

976 Lake Baldwin Lane

Orlando, FL 32814

USA

Tel: (407)895-0802

Email: staff@birthdefects.org

Internet: http://www.birthdefects.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



Perkins School for the Blind

175 North Beacon Street

Watertown, MA 02472

Tel: (617)924-3434

Fax: (617)926-2027

Email: Info@Perkins.org

Internet: http://www.Perkins.org



National Consortium on Deaf-Blindness

The Teaching Research Institute

345 N. Monmouth Avenue

Monmouth, OR 97361

Tel: (800)438-9376

Fax: (503)838-8150

Tel: (800)438-9376

TDD: (800)854-7013

Email: info@nationaldb.org

Internet: http://www.nationaldb.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:  5/22/2008

Copyright  1986, 1992, 1994, 2000, 2001, 2004 National Organization for Rare Disorders, Inc.

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