Edward's Syndrome

From The School of Biomedical Sciences Wiki
Revision as of 19:30, 9 December 2018 by 180220197 (Talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Edward's Syndrome is a genetic disorder caused by a trisomy of chromosome 18 (where there are three copies of chromosome 18). This affects approximately 1 in 3000-5000 live births. Common symptoms include, but are not limited to, an abnormally shaped head with a small jaw, heart and kidney problems and bone abnormalities[1].

Edwards Syndrome occurs when there is a defect to chromosome 18, making this syndrome a genetic defect

There are two different types of problem that can occur about the chromosome. There may be a full trisomy of chromosome 18 or there maybe a mosaic trisomy wherein only some cells are there full trisomys.

This rare syndrome is three times more common in females rather than males. It is usually only seen in the foetus however when a baby is born with it their life expectancy is very low with serious complications. The complications that may occur are very widespread but are usually most severe in the brain, heart, stomach, kidney and skull[2].

Physical signs of Edward's syndrome include:

The majority of babies with Edward's syndrome are miscarried or stillborn This occurs due to the chromosomal abnormality the pregnancy cannot progress properly and the functioning of the pregnancy is abnormal. However miscarriages aren’t always the case and parents have to make the choice whether to terminate their pregnancy. After screening parents are advised to terminate the pregnancy due to how serious the disease is and the chances of survival are slim after birth, with many babies surviving only a few days. [3] 33.3% of babies born alive usually die due to severe medical problems. The few that do live longer will live with severe disabilities. However, those born with just the mosaic and partial forms can live longer, into their adult years.

Edward's syndrome is rarely inherited. Trisomy 18 (developing three copies of chromosome 18) usually happens randomly during the formation of eggs and sperm. There is an error in the division of cells and the extra chromosome is either in the egg cell produced by the mother or in the sperm cell produced by the father.

Because this happens randomly, it's extremely unlikely for parents to have more than one pregnancy affected by Edward's syndrome.

Contents

Types of Edward's Syndrome:

Full form:

The most common form, where cells have 3 copies of chromosome 18, instead of the regular 2. Most will die before infancy.

Mosaic trisomy 18:

Here the babies have the extra copy of chromosome 18 in only some of the body cells, therefore this form is less severe. The severity depends on the type and number of cells that have the extra chromosome. Some babies may only be mildly affected, while some can be severely disabled.

Partial trisomy 18:

The babies still have an extra copy of chromosome 18, however just a part/segment of it. Similarly, the severity depends on the size of the segment that is tripled. The affects on the baby, therefore, have a wider range, from very less affected to heavily disabled.

Testing for Edward's syndrome during pregnancy:

These invasive tests allow parents to opt for termination of the pregnancy. Almost every time, signs that the baby may be affected are picked up at the 'routine 18-20 week ultrasound fetal anomaly scan' or via a blood test for Down syndrome. Chorionic villus sampling (CVS) or amniocentesis tests detect whether the foetal development will become or already has become abnormal. There is no cure for Edward's syndrome[4].

References

  1. NHS. (2012). Edwards Syndrome. Available: http://www.nhs.uk/conditions/edwards-syndrome/Pages/Introduction.aspx. Last accessed 25th Nov 2013
  2. (2009), Edwards Syndrome, http://www.chromosome18.org/. Last accessed 17/10/13
  3. conditions C. Edwards' syndrome [Internet]. BabyCentre UK. 2018 [cited 6 December 2018]. Available from: https://www.babycentre.co.uk/a1024183/edwards-syndrome
  4. http://www.nhs.uk/conditions/edwards-syndrome/Pages/Introduction.aspx
Personal tools
Namespaces
Variants
Actions
Navigation
Toolbox