Down Syndrome

Essay by island_diva March 2004

download word file, 3 pages 5.0

Down Syndrome, a chromosome abnormality is present in all ethnicity, social economic classes, and gender. In, Down Syndrome is defined as a "congenital disorder by an extra chromosome on the chromosome 21 pair." Although there are many theories that have been forwarded for the cause of chromosome abnormalities, there is no known research for the cause of Down Syndrome. There are three main types of chromosome abnormalities in Down Syndrome. They are Trisomy 21, Mosaic Down Syndrome, and Translocation Down Syndrome. All three types have similar characteristics and it is known that children with Down Syndrome require more time to master skills such as walking and talking. Services, however, are being provided to educate and help children with this disability.

In 1866, John Langdon Down wrote an essay describing a particular group of children that had similar features with mental retardation. He stated that "these children looked liked people from Mongolia," therefore referring to them as Mongoloids.

However, in the early 1960s, Asian researchers were insulted by the term and changed it to "Down's Syndrome." Although the term Down's Syndrome is still used in the United Kingdom and some places in Europe, in 1970 it was changed to "Down Syndrome."

Human cells normally have 46 chromosomes and divide in two ways. The first ordinary cell division is the baby's development and is called "mitosis." In this method, one cell splits into two. The second method of cell division is called "meiosis" and this, similar to the mitosis method, involves one cell to split into two. This method, however, occurs in the ovaries and testicles.

The most common type of Down Syndrome is Trisomy 21. This type affects about 90 to 95 percent of the people with Down Syndrome. This type of syndrome takes place prior to conception and...