Trisomy

Trisomy is a type of Aneuploidy; change from the wild type in the number of chromosomes. Trisomy is the presence of an extra counterpart of a chromosome in addition to the pass judgment two. Examples of Trisomy are megabucks syndrome (Trisomy 21) and tercet X syndrome (Trisomy X). In the mid 19th century, English medico rump Langdon cumulus studied children with mental retardation. flock noniced that the children displayed a range of symptoms. What go across noticed were some physical displays of the Down syndrome phenotype. He saw that children with Down syndrome had eyes that slanted upward, a flat nose, an abnormally large tongue, and had an overall shorter life expectancy. steady with his findings Down did not pinpoint the cause of the syndrome. This happened well-nigh a century later. Why was there such a vast gap between Downs initial findings and the uncovering of Trisomy 21? It was simply because at the time the technology did not exist to take note chromo somes and karyotypes. In 1959 with the technology open to observe human chromosomes, France and Patricia Jacobs were able to identify that an extra copy of chromosome 21 in karyotypes of DS individuals.

Patricia Jacobs also the first to register a clear case of Trisomy X in 1959, apply the same(p) methods she used to observe Trisomy 21. Besides the visible facial characteristics of Down Syndrome the phenotype displays many more conditions: short stature, heart defects, susceptibility to respiratory disease, shorter life span, gastrointestinal abnormalities 3 forms of Down syndrome exist: the anticipate Trisomy 21 which accounts for active 95% of cases, Familial! Down Syndrome which accounts for about 4% of cases, and the remaining 1% of cases are of Mosiac Down Syndrome.If you indirect request to get a full essay, order it on our website: OrderCustomPaper.com

If you want to get a full essay, visit our page: write my paper