Trisomy 21: Down Syndrome Essay

611 Words 3 Pages
This person has three copies of one of their chromosomes instead of two. This is known as trisomy. The chromosome that is affected in this individual is chromosome 21.
Although chromosome 21 is the smallest one humans have, it can cause a lot of problems if it is altered. This includes several kinds of cancers, such as a type of leukemia. It can also effect mental development and growth.
Since this person has three chromosome 21's instead of two, this means that they have Down syndrome. It was identified as being a chromosome 21 trisomy in 1959 by Dr. Jérôme Lejeune. Down syndrome is named after John Langdon Down, a british physician who wrote about the syndrome in 1866. It is also the most common chromosome abnormality in humans. In the
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Even when they do manage to conceive, about half of the children will also have Down Syndrome, and there are usually complications such as miscarriage.

One of the ways it almost always appears is a decrease in IQ and mental capability. The average individual has an IQ of 100, whereas an average person with the syndrome's IQ is 50. One with Down Syndrome may not learn to talk, walk, and perform various other tasks as soon as other children. Later on in life, they are at risk for epilepsy. Alzheimer's is also probable.
The syndrome can also cause neotinization, which means they retain childlike features as they age. It can result in stunted growth, and cause several physical abnormalities.

These abnormalities are likely to cause those with it to have distinctive facial features and a unique appearance. A broad, flat face is common, and they may have an overly large tongue or small ears. The person may also have a small chin and a short neck. Poor muscle tone and smaller fingers are also a result.. Finally, they tend to be smaller overall than somebody without it.

Down syndrome usually affects the senses. Sight and hearing are the senses most often impacted by it.
The syndrome can cause those with it to have hearing loss very early on. In some cases, hearing aids are necessary. It can also result in frequent ear infections.
It negatively affects eyesight as well. They have an increased chance to get

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