Different Types Of Down Syndrome

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Down syndrome was discovered in the 1800’s by a man named John Langton Down. Down syndrome1 is a condition that occurs in the chromosomes. The syndrome affects the intellectual ability of the person effected, their facial appearance and causes hypotonia2. Children born with this usually experience different types of birth defects. These birth defects can include heart defects and intestine blockage. People with Down syndrome are also at a high risk of developing other medical conditions. Some medical conditions include gastro esophageal reflux3, celiac disease4, hypothyroidism5, and leukemia6. Also some visual and hearing problems can arise. There are three types of Down syndrome. The three types are Trisomy 21, translocation and mosaicism. Trisomy 21 is also known as nondisjunction. Usually a person has two separate copies of chromosome 21. In nondisjunction, the embryo develops three copies. During or before a child is conceived, in the egg or sperm cell, a pair of the 21st chromosome7 fails to separate. About 95% of Down syndrome cases are caused from Trisomy 21. The second genetic mutation of Down syndrome is translocation. Translocation is when a part of chromosome 21 breaks off and attaches to another chromosome. The chromosome that it usually gets attached to is chromosome 14. Translocation accounts for around 4% of Down syndrome cases. The last genetic mutation of Down syndrome is mosaicism. Mosaicism happens when nondisjunction of chromosome 21 in one of the first cell division after the egg has been fertilized. Although it happens in one of the first cell divisions, it does not necessarily have to happen in all cell divisions. Mosaicism accounts for about 1% of Down syndrome cases. This paper wil... ... middle of paper ... ...ides to wait to have child, the chances of their baby having Down syndrome increase. If a person has a child at the age of 20, there is a 1 in 2,000 chance the child will develop Down syndrome. If the woman waits until she is 30 years of age, there is a 1 in 900 chance her child will have Down syndrome. If the woman waits even longer until she is 45, there is a 1 in 30 chance her child will have Down syndrome. More women are decided to wait to have children, making the chance that a child will be born with Down syndrome go up drastically. If a parent has already given birth to a child with Down syndrome, the chance that they will have a child with Down syndrome is about 1 in 100. In 1983, the life span of someone with Down syndrome was estimated to be 25 years of age. Now it is estimated that a person with Down syndrome will live to be about 60 years of age.

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