What is Edwards Syndrome

Edwards syndrome is a genetic disorder more commonly known as Trisomy 18.  It occurs when a baby has three instead of two copies of chromosome 18.

What exactly is Edwards syndrome?

This condition is fairly common.  According to the Trisomy 18 Foundation, it occurs in around 1 out of every 3,000 live births.  Researchers believe the disorder occurs even more frequently when they consider babies lost during the second and third trimester.

Around half the Edwards syndrome babies carried until term are stillborn.   More of these stillborn births are of boys than girls.  MedlinePlus reports that overall, however, this disorder is three times more common in girls than boys.  Doctors associate it with potentially life-threatening complications throughout the child’s first few years. 

Is it related to Down syndrome?

The only connection is that the cause of both syndromes is a trisomy.  In the case of Down syndrome, however, a baby has three copies of chromosome 21 instead of 18.

Health care providers consider the complications associated with Edwards more potentially life-threatening early in a child’s life than those of Down syndrome.

What causes Edwards syndrome?

A baby normally inherits 23 chromosomes each from the mother and the father, for a total of 46 in each cell.  A trisomy happens when three chromosomes appear instead of two. 

This event just happens at conception.  The extra chromosomal material interferes with the baby’s normal development.

What are symptoms?

The list of symptoms is long and varies somewhat from one child to another.  However, some of the most common include the presence of clenched hands or crossed legs, feet with rounded bottoms and low-set ears.

Many Edwards children have a low birth weight, small head, small jaw and mental deficiency.  Underdeveloped fingernails, an undescended testicle and a chest with an unusual shape are also common.  Some babies suffer from an umbilical hernia, a hole or split in the iris, congenital heart disease or kidney problems.

What are the different types?

The Trisomy 18 Foundation indicates there are three types of this condition:

Full Trisomy 18.  This makes up around 95 percent of all cases of Edwards syndrome.  The extra chromosome appears in every cell of the baby’s body.  Doctors don’t consider this type hereditary or due to anything the parents did before or during the pregnancy.

Partial Trisomy 18.  This variety occurs when only a portion of an extra chromosome is present in cells. It’s very rare.  Some of these cases might be the result of hereditary factors.  Experts believe that in rare instances, a piece of chromosome 18 attaches to another chromosome before or after conception. 

Mosaic Trisomy 18.  When an extra chromosome 18 occurs in only some cells, the baby has this type of rare trisomy.  Doctors believe it’s the result of a random event, not heredity.

What is the prognosis of Edwards syndrome?

Among live births, a full fifty percent of babies don’t survive more than a week.  Although some children have reached adolescence, they experienced significant medical and development issues.

Complications of Edwards syndrome are linked to the patient’s particular symptoms and defects.  Since children experience varying degrees of severity, treatment for the disorder must be customized to each patient.