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.
- Chromosome 18, Trisomy 18 Complete
- Complete Trisomy 18 Syndrome
- Edward's Syndrome
- Trisomy E Syndrome
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.
Support Organization for Trisomy 18, 13, and Related Disorders
2982 South Union Street
Rochester, NY 14624-1926
Arc (a national organization on mental retardation)
1010 Wayne Ave
Silver Spring, MD 20910
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.
800 Celebration Ave, Suite 225
Orlando, FL 34747
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 St.
Watertown, MA 02472
National Consortium on Deaf-Blindness (NCDB)
The Teaching Research Institute
Western Oregon University
345 N. Monmouth Ave.
Monmouth, OR 97361
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This is an abstract of a report from the National Organization for Rare Disorders, Inc. ® (NORD). A copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html