Trisomy 18 Syndrome
National Organization for Rare Disorders, Inc.
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 Back to top
- Chromosome 18, Trisomy 18 Complete
- Complete Trisomy 18 Syndrome
- Edward's Syndrome
- Trisomy E Syndrome
Disorder Subdivisions Back to top
General Discussion Back to top
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 Back to top
Support Organization for Trisomy 18, 13, and Related Disorders
2982 S. Union Street
Rochester, NY 14624-1926
1660 L Street, NW, Suite 301
Washington, DC 20036
Support Organization for Trisomy 13/18 and Related Disorders, UK
c/o Christine Rose
48 Froggatts Ride
West Midlands, Intl B76 2TQ SOFT
UNIQUE - Rare Chromosome Disorder Support Group
P.O. Box 2189
Surrey, Intl CR3 5GN
Tel: 44 0 1883 330766
Fax: 44 0 1883 330766
Birth Defect Research for Children, Inc.
976 Lake Baldwin Lane
Orlando, FL 32814
MUMS National Parent-to-Parent Network
150 Custer Court
Green Bay, WI 54301-1243
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
PO Box 241956
Los Angeles, CA 90024
Let Them Hear Foundation
1900 University Avenue, Suite 101
East Palo Alto, CA 94303
Perkins School for the Blind
175 North Beacon Street
Watertown, MA 02472
National Consortium on Deaf-Blindness
The Teaching Research Institute
345 N. Monmouth Avenue
Monmouth, OR 97361
For a Complete Report Back to top
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 email@example.com
Last Updated: 5/22/2008
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