Trisomy
18 (Edwards' Syndrome)In this chromosomal abnormality there is an extra
copy of chromosome 18 . It occurs with a frequency of 1 in 6500 births.
This is a syndrome with many serious malformations that interfere with a normal
life expectancy. About half of the pregnancies die spontaneously due to severe
malformations incompatible with life. Of the remainder half will die within the
first 2 months, so that only 5% to 10% will survive the first year. However, the
multitude of malformations severely limits their long-term survival. Signs
and symptoms The child is usually born with a low birth weight,
has a small mouth (microstomia) and a small jaw (micrognathia). This tends to
interfere with the normal feeding process. There is a small head (microcephalus)
with an oversized back of the head (prominent occiput), low set malformed ears,
flexion deformities of fingers and rocker-bottom feet. Here is an image
with the described malformations. In addition these children have
severe mental problems due to a brain deformity with additional folds on the brain
surface (extra gyri). Congenital kidney and heart abnormalities may be the life
limiting abnormalities in addition to the mental retardation. The most
devastating fact is that 99% of children born with Edward syndrome have congenital
heart disease, ventricular septal defect, patent ductus arteriosus or pulmonary
stenosis. X-ray images reveal that there are hypoplastic ribs with only
11 pairs, there is a gap between the 2nd and 3rd fingers and there is a small
pelvis with sloping acetabula (malformation of the hip socket.) Another
typical malformation is a defect of the iris of the eye, called coloboma.
Treatment As this is a genetic syndrome,
there is no treatmentavailable. These individuals will need to live in a supportive
environment and often end up in a specialized home that is equipped to deal with
these patients.
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