What is Edwards Syndrome?
Edwards Syndrome is clinically known as Trisomy 18. What this means is that at the 18th chromosome set, where a person unaffected by Edwards, there are only two chromosomes. However in the case of a person with Edwards, there will be a third chromosome, hence the name Trisomy (three chromosome) 18. Edwards Syndrome however is unlike Down syndrome in the fact that the complications caused by Edwards are medical complications that are potentially more life threatening. If a child with Edwards is carried to term, there is a 50% stillbirth rate, and of this 50%, there is a higher rate of boys stillborn than girls. [1]
Edwards Syndrome is a lot more deadly than Down Syndrome. A person who is affected by Down syndrome will live into adulthood. This is not the case with Edwards. Because of Edwards lethality, if a baby is carried to term and survives birth, it will most likely die before 2 months old. [1]
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Edwards Syndrome is a lot more deadly than Down Syndrome. A person who is affected by Down syndrome will live into adulthood. This is not the case with Edwards. Because of Edwards lethality, if a baby is carried to term and survives birth, it will most likely die before 2 months old. [1]
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Edwards Syndrome has three different variations. This first and most common type (95% of all Trisomy 18 cases) is Full Trisomy 18. This is where a complete extra chromosome is in the 18th set. The second (very rare variation) is Partial Trisomy 18. This is where only part of a third chromosome is in the 18th chromosome set. The last is Mosaic Trisomy 18. Mosaic Trisomy 18 is also very rare and is where there is three chromosomes in some, however, not all cells in the body. [1]
Differences Between normal Human Condition And Edwards Syndrome
In a person unaffected by Edwards, when they are conceived, an egg and a sperm come together and become one. Both the egg and the sperm have 23 chromosomes each. When these two lots of chromosomes come together, the correct number of chromosomes for human life (46 chromosomes, or 23 pairs) are put together in a single cell. From this, they form the cell which will replicate and divide to eventually become a foetus and embryo. As this is done, a complete replica of the original cell is and the DNA that is contained within it is replicated. Every single cell that will come from the division will be an exact replica of the original cell.
In the case of diseases like Edwards Syndrome, one of the sex cells (either the sperm or the egg) has instead 24 chromosomes instead of 23. This means that one of the chromosomes doubled up. When the egg and sperm come together, the cell that is formed has 47 chromosomes instead of of the 46. However, there is still 23 sets of chromosomes in the original cell. this means that instead of all 23 sets being pairs, one of the sets has to be a triplet. In the case of Edwards Syndrome, it is the 18th set that is the triplet. This leads to the affects of Edwards Syndrome.
Like normal cell division, every cell that is divided will be an exact copy of the original. This means that every cell will have an error and will lead to all the problems associated with Edwards Syndrome. Since there is to much genetic information in the cells, they will be unable to function properly. This will lead to malformities and deformaties in the child's cells, and therefore body. As the body is not properly formed it will not work as it is meant to and will therefore be unable to sustain prolonged life.
In the case of diseases like Edwards Syndrome, one of the sex cells (either the sperm or the egg) has instead 24 chromosomes instead of 23. This means that one of the chromosomes doubled up. When the egg and sperm come together, the cell that is formed has 47 chromosomes instead of of the 46. However, there is still 23 sets of chromosomes in the original cell. this means that instead of all 23 sets being pairs, one of the sets has to be a triplet. In the case of Edwards Syndrome, it is the 18th set that is the triplet. This leads to the affects of Edwards Syndrome.
Like normal cell division, every cell that is divided will be an exact copy of the original. This means that every cell will have an error and will lead to all the problems associated with Edwards Syndrome. Since there is to much genetic information in the cells, they will be unable to function properly. This will lead to malformities and deformaties in the child's cells, and therefore body. As the body is not properly formed it will not work as it is meant to and will therefore be unable to sustain prolonged life.
[1] AFP Testing - Trisomy 18 Foundation . 2014. AFP Testing - Trisomy 18 Foundation . [ONLINE] Available at:http://www.trisomy18.org/site/PageServer?pagename=whatis_afp. [Accessed 7 August 2014].
[2] What is Trisomy 18? - YouTube. 2014. What is Trisomy 18? - YouTube. [ONLINE] Available at: https://www.youtube.com/watch?v=kCe5zCrgFcU. [Accessed 7 August 2014].
[2] What is Trisomy 18? - YouTube. 2014. What is Trisomy 18? - YouTube. [ONLINE] Available at: https://www.youtube.com/watch?v=kCe5zCrgFcU. [Accessed 7 August 2014].