Down Syndrome Chromosome Twenty One

Down Syndrome Chromosome Twenty One Down syndrome affects one out of 700 children born in the United States. A chromosomal disorder associated with the twenty first chromosome pair, brings a lifetime of challenges to the affected person. Down syndrome is associated with intellectual disability, a characteristic facial appearance and reduced muscle tone during infancy as stated by Genetics Home Reference (2013). There are three different scenarios in which Down syndrome can occur. Down syndrome typically occurs as the result of having an extra twenty first chromosome. This extra twenty first chromosome can be seen in the picture to the left. This extra chromosome in the cell happens as a mistake that takes place during cell division between the female’s egg cell and the male’s sperm cell. This error in cell division, known as nondisjunction, is the cause of 95% of Down syndrome births. This is also referred to as Trisomy 21. Another cause of Down syndrome is when the cells have the correct number of chromosomes to begin with after fertilization, but when the cells are rapidly dividing one or more of the cells can end up with an extra chromosome twenty one. This way of getting down syndrome, known as cell line mosaicism is rare, and the person shows less severe signs of the typical Down syndrome disorder. The third scenario of Down syndrome is also rare and is caused by having the normal number of chromosomes but a whole chromosome twenty one being attached to another set of chromosomes. This is called Robertsonian translocation and occurs in about three to four percent of Down’s syndrome cases. The disease of Down syndrome is not found within a certain gender or race. Down syndrome is however found equally between a... ... middle of paper ... ... of through surgery or therapy. However people with Down syndrome tend to be very kind hearted people and good easy going people. They can still preform everyday task as normal people without the disease can. People with Down syndrome can still go to work and have jobs. These jobs however should be an easier job than usual. References Chromosome 21. (2013, November 1). Retrieved January 22, 2014, from Genetics Home Reference website: http://ghr.nlm.nih.gov/chromosome/21 Down syndrome. (2008). In K. L. Lerner & B. W. Lerner (Eds.), The gale encyclopedia of science (4th ed.). Retrieved from Gale Student Resources in Context database. (Accession No. CV2644030714) Winders, P. C., PT. (n.d.). Physical Therapy & Down Syndrome. Retrieved from National Down Syndrome Society website: http://www.ndss.org/Resources/Therapies-Development/Physical-Therapy-Down-Syndrome/