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Edwards Syndrome

Related Terms: lymphedema, lymphatic dysplasia, chromosomal disorder, trisomy 18, chromosome, Dysgenesis of corpus callosum, Edwards Syndrome, Oesophageal atresia, Renal agenesis, Ultrasound, Phenotype-karyotype correlations, Duplication of 18q

Edwards Syndrome, also known as Trisomy 18, is the second most common trisomy syndrome. It occurs in 1/3000 to 1/8000 births. The condition presents with numerous developmental disorders and malformations. The median life span of children with ED is about 2 weeks, and only 5%-10% will survive their first year. (1)

Girls are three times more likely to have Edwards Syndrome then boys.


Most cases of trisomy 18 result from having three copies of chromosome 18 in each cell in the body instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of trisomy 18.

Approximately 5 percent of people with trisomy 18 have an extra copy of chromosome 18 in only some of the body's cells. In these people, the condition is called mosaic trisomy 18. The severity of mosaic trisomy 18 depends on the type and number of cells that have the extra chromosome. The development of individuals with this form of trisomy 18 may range from normal to severely affected.

Very rarely, the long (q) arm of chromosome 18 becomes attached (translocated) to another chromosome during the formation of reproductive cells (eggs and sperm) or very early in embryonic development. Affected people have two copies of chromosome 18, plus extra material from chromosome 18 attached to another chromosome. If only part of the q arm is present in three copies, the physical signs of translocation trisomy 18 may be different from those typically seen in trisomy 18. If the entire q arm is present in three copies, individuals may be as severely affected as if they had three full copies of chromosome 18.


This list may not be inclusive:

•Clenched hands •Crossed legs (preferred position) •Feet with a rounded bottom (rocker-bottom feet) •Low birth weight •Low-set ears •Mental deficiency •Small head (microcephaly) •Small jaw (micrognathia) •Underdeveloped fingernails •Undescended testicle •Unusual shaped chest (pectus carinatum)


Diagnosis is made through a variety of exams, and tests. A physical exam can show an unsually large uterus or a higher then normal amount of amniotic fluid. It can also show fingerprint patterns, and a short breast bone. Upon birth, a small placenta may be noticed.

Other disgnostic signs include:

•Hole, split, or cleft in the iris (coloboma) •Separation between the left and right side of the rectus abdominis muscle (diastasis recti) •Umbilical hernia or inguinal hernia

Signs of congenital heart disease, such as Atrial septal defect (ASD), Patent ductus arteriosus (PDA), Ventricular septal defect (VSD) may also be present.

There may also be kidney difficulties including: Horseshoe kidney, Hydronephrosis , Polycystic kidney However, according to A Trisomy 18 Journey – Edwards Syndrome Resources the only way to conclusively determine a correct diagnosis is to do a amniocenteses or CVS (chronis villi sampling). This is an excellent site and I would recommend any one dealing with Edwards Syndrome or desiring to understand the condition to take the time to read through the website. The site includes a section of patient stories


As one might imagine, treatment courses are planned on a case=by-case basis and will depend upon the number and severity of comorbidities.

Even possible treatment can be a controversial subject and heroic measures to try to prolong life for infants born with complete trisomy 18 are generally not recommended, by some.

Treatment may be done surgically for abnormalities of his or her body such as heart, kidney, or genital malformations. Infections should also be treated accordingly since there is a higher risk for middle ear infection, pulmonary infection, and urinary tract infection. Some children may benefit from psychological counseling as well as academic support to avoid depression, social isolation and difficulties at school. On the milder end of the mosaic spectrum, a minimally affected child will be treated the same way one would treat a normal child. It is important to raise a special child in an encouraging and supportive environment. (2)


Complete trisomy 18 is usually incompatible with life, hence the mortality (death) rate is high in the form of miscarriages and the live birth of such an infant is a rare event. If live born, the abnormalities of trisomy 18 are generally so severe that fifty percent of these infants do not survive more than the first week and less survive for a few months. More than 10 children have been known to survive to teenage years, but have usually marked handicaps (2)

(1) Trisomy 18 (2) Madisons Foundation

Abstracts and Studies

Clinical courses of Edwards syndrome - an update.

June 2011

[Article in German]

Thiel M, Blanke P, Längler A.

Source Gemeinschaftskrankenhaus Herdecke, Abteilung für Kinder- und Jugendmedizin, Herdecke.


Key words: trisomy 18 - ethical questions - parental wishes - poor prognosis


In current literature the prognosis of trisomy 18 is mainly described as inevitably lethal. After intervention of parental organisations infants have been treated with cardio surgery in the USA, later in Europe as well with good results. We report the consequences of this and similar developments on our pre- und postnatal approach after diagnosis in our department.


2 parents decided to carry the child to term after the recommendation for abortion. According to standard perinatological aspects one child was vaginally delivered, the second with Caesarean section. After informed consent with the parents we planned a supportive management without more resuscitation than stimulation and ventilation by mask. Both children could be stabilised with nasal CPAP. The first one had been operated on a double outlet right ventricle at the age of 6 months, the second needed to be operated for diaphragm hernia. The third child had been delivered by emergency Caesarean section. A bilateral choanal atresia had been operated in the first week of life, a double outlet right ventricle at the age of 15 days. One child is fed by a nasogastric tube, one is bottle-fed and one had a percutanous gastric tube until he died due to septicaemia, all have statomotorically retardation and had periods of pulmonary hypertension. The social situation of the families is characterised by a stable parental relationship and a safe socio-economical status. None of the children had an acute lethal malformation.


In single cases a prospective management in patients with trisomy 18 can be possible. Besides medical issues, the emotional parental wish, their social network and economical status are crucial.


The prognosis of trisomy 18 is poor. 3 patients and 20 months do not allow any general statements. However, our recent experience and the courses in the recent literature show that in single cases a more prospective


Unusual clinical history of a male infant with Edwards syndrome.

March 2009

Surányi A, Bitó T, Vajda G, Kaiser L, Gáspár G, Katona M, Szabó J, Pál A. Source Department of Obstetrics and Gynaecology, University of Szeged, Szeged 6725, Semmelweis u. 1. 438, Szeged, Hungary.


Keywords Dysgenesis of corpus callosum - Edwards syndrome - Oesophageal atresia - Renal agenesis - Ultrasound

Edwards syndrome (trisomy of chromosome 18) is generally characterized by the disorders of central nervous system, as well as the musculoskeletal and genitourinary systems. In majority of the cases with trisomy 18 the following malformations can be found: ventricular septal defect, horseshoe kidneys, oesophageal atresia, omphalocele, facial clefts, diaphragmatic hernias and genital hypoplasia. We report a male patient with Edwards syndrome. The boy had a partial agenesis of corpus callosum, oesophageal atresia with tracheo-oesophageal fistula, renal agenesis, ventricular septal defect, Dandy-Walker cyst and low-set malformed ears. The first three features are unique based on previous literature reports on trisomy 18. This report allows a further delineation of the trisomy 18 syndrome.


Edwards syndrome with double trisomy.

July 2008

Tennakoon J, Kandasamy Y, Alcock G, Koh TH. Source Neonatal Intensive Care Unit, The Townsville Hospital, Douglas, QLD 4814, Australia.


Double trisomy is rare and the only case reported in the literature died soon after birth. We present another case of double trisomy (48XYY, +18) in a male neonate, who was born to a 28-year-old gravida three parity one mother at 35 weeks of gestation. The baby had features of trisomy 18. Karyotype of the patient showed 48, XYY, +18, Ish (DYZ3*2), (D18Z1*3), nuc ish (DYZ3*2), (D18Z1*3) . The patient had clinical features of trisomy 18. There was no family history of diabetes mellitus and no exposure to chemicals. It has been suggested that the rarity of Y-chromosome involvement in trisomy 18 may be due to discrepancy between the sexes.


External Links

Support Groups and Resoures

A Trisomy 18 Journey – Edwards Syndrome Resources Trisomy 18 Foundation 4301 Connecticut Ave. N.W. Suite 404 Washington, D.C. 20008-2369 757-464-5905

Support Organization for Trisomy 18, 13, and Related Disorders (SOFT) Trisomy Families 2982 S Union St Rochester, NY 14624 716-594-4621 800-716-7638

Hope for Trisomy 13 & 18

SOFT: Support Organization for T18, T13 & Related Disorders 2982 S Union Street Rochester, New York, USA 14624 (585) 594-4621 800-716-SOFT (toll-free)

Lucille Packard Children’s Hospital at Stanford

Madisons Foundation

UT Health Science Center – Chromosome 18 Clinical Research Center


Orphanet Lists of International Networks

Support Groups for Chromosomal Conditions

National Organization for Rare Disorders

Classifications and Description


Q91 Edwards' syndrome and Patau's syndrome Q91.0 Trisomy 18, meiotic nondisjunction Q91.1 Trisomy 18, mosaicism (mitotic nondisjunction) Q91.2 Trisomy 18, translocation Q91.3 Edwards' syndrome, unspecified


2008 ICD-9-CM Diagnosis 758.2

Edwards' syndrome

A syndrome characterized by the presence of an extra (third) chromosome on an otherwise diploid chromosome 18 associated with a broad spectrum of variable abnormalities consisting of more than 130 individual defects of the craniofacial structures, brain, heart, kidneys, and gut. One-third of newborn infants (weighing about 2300) are premature and two-thirds are female. Fetal abnormalities consist mainly of polyhydramnios, small placenta, and single umbilical artery. Tumors in some cases. Trisomy 18 mosaicism is often associated with normal intelligence and mild phenotype.

•758.2 is a specific code that can be used to specify a diagnosis •758.2 contains 21 index entries •View the ICD-9-CM Volume 1 758.* hierarchy

758.2 also known as:

•Trisomy: o18 oE3

eMedicine: ped/652

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edwards_syndrome.txt · Last modified: 2012/10/16 14:40 (external edit)