Chromosomal disorder characterized by a broad spectrum
of variable dysmorphic features and organ malformations with extremely poor
prognosis (90% of patients die before 1 year of age).
Edwards Syndrome; Trisomy E.
Chromosomal disorder described simultaneously by Edwards,
Patau, and Smith teams in 1960.
Incidence is about 1 3,000 to 8,000 live births.
Two-thirds of the cases are diagnosed at the time of amniocentesis and are
spontaneously aborted before delivery. It is the second most common
autosomal aberration and second most common multiple malformation syndrome.
Risk factors include advanced maternal age. Girls are approximately 4 times
more often affected than boys. The prognosis after delivery is poor with a
10% survival at 1 year, however survival into adulthood has been
described. When mosaicism occurs, patients can have a normal intelligence
and a mild phenotype.
Mostly sporadic with less than 1% risk of
recurrence. Ninety percent are believed to be associated to meiotic nondisjunction (Trisomy 18
presentation). Mosaicism is suspected in 10% of the cases and because of
postzygotic mitotic nondisjunction. It leads to partial clinical expression
of Trisomy 18 with a longer survival rate. Translocations are very rare.
The diagnosis is most often already made in utero
following an amniocentesis or ultrasound examination. Otherwise a chromosome
study after birth confirms the diagnosis if there is clinical suspicion
based on the pattern of malformations.
More than 130 different abnormalities have been
reported in the literature and so only the more common ones will be listed
here. Fetal abnormalities consist mainly of polyhydramnios, small placenta
with single umbilical artery, and growth deficiency. Neurologically, the
patients present with mental deficiency, microcephaly, and hypertonicity.
They also have a prominent occiput with a narrow bifrontal diameter. Other
craniofacial anomalies consist of low-set, malformed ears, short palpebral
fissures, microstomia, narrow palatal arch, and micrognathia. Numerous
musculoskeletal abnormalities are present like the characteristic clenched
hand with overlapping fingers, short dorsiflexed halluces, short sternum,
small pelvis, and limited hip abduction. Cutaneous problems consist of
redundancy, mild hirsutism of the forehead and back, and prominent cutis
marmorata. Cardiac investigation often finds an atrial or ventricular septal
defect, a persistent ductus arteriosus, or coarctation of the aorta. Less
frequent anomalies may include malformation or absence of the right lung,
diaphragmatic muscle hypoplasia, renal malformations, and cleft lip and
These children are very sick and
most of them will die in their first year of life as a consequence of the
trisomy. If they present for anesthesia, it is imperative to obtain a
thorough cardiopulmonary evaluation, including echocardiography,
electrocardiogram, and chest radiograph, and an arterial blood gas analysis
should be considered. Blood work should include a complete cell blood count and serum
concentrations of electrolytes, creatinine, and urea. Evaluate the airway
for signs of difficult management.
Direct laryngoscopy and tracheal
intubation may be difficult because of some of the features of the disease