History of Down's Syndrome

Down’s Syndrome is named after John Langdon Down, a British doctor who first studied and described the mental disorder. He discovered the disorder in Surrey, England while working at an asylum for children with mental retardation. He called people with this disorder Mongoloids because of the physical similarities of citizens from Mongolia compared to those affected by Down’s Syndrome. Later, the term “Mongoloid” was dropped and named after John Down when Jerome Lejeune, a French geneticist who tested children with these similar physical characteristics of Mongolians, found that 97% of those tested had an extra chromosome-21, with a total of 47 chromosomes. Down’s Syndrome is a common disorder due to an extra chromosome number; it is the most common cause of mental retardation that occurs in 1 in 1,000 babies in the United States. (Genetic Science Learning Center)

There are three types of Down’s Syndrome: Trisomy 21, Translocation, and Mosaicism. Trisomy 21 is the most common type of Down’s Syndrome; it occurs in 95 percent of Down’s Syndrome cases. Trisomy 21 is a disorder in which a newborn receives an extra third chromosome-21, instead of the normal 2. The second type of Down’s Syndrome is Translocation; it occurs when only a small piece of the chromosome-21 is found on another chromosome. Only 3 percent of those with Down’s Syndrome suffer from Translocation. Mosaicism is the third type of Down’s Syndrome and also the rarest; it is a disorder in which newborns have a mix of cells in the chromosome-47 that contains an extra chromosome-21. Only 2 percent of people with Down’s Syndrome possess Mosaicism. (Hauser-Cram, 15)

Causes of Down’s Syndrome are still unknown. There is no way to prevent the occurrence of Down’s Syndrome,...

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Hauser-Cram, Penny. Children with Disabilities: a longitudinal study of child

development and parent well-being. Boston: Blackwell, 2001.

Kumin, Libby. Classroom Language Skills for Children with Down Syndrome: A Guide

for Parents and Teachers. 1st ed. Maryland: Woodbine House, 2001.

Leshin, Dr Len. Down Syndrome: Health Issues. May 2009.

McGuire, Dennis. Mental Wellness in Adults with Down Syndrome: A Guide to

Emotional and Behavioral Strengths and Challenges. 1st ed. Maryland: Woodbine

House, 2006.

Skallerup, Susan, ed. Babies with Down Syndrome. 3rd ed. Boston: Woodbine House,

2008.

Skotko, Brian. Fasten Your Seatbeat: A crash course on Down Syndrome for brothers

and sisters. 1st ed. Maryland: Woodbine House, 2009.