Trisomy

Trisomy is a type of Aneuploidy; change from the wild type in the number of chromosomes. Trisomy is the presence of an extra model of a chromosome in addition to the pass judgment two. Examples of Trisomy are megabucks syndrome (Trisomy 21) and double X syndrome (Trisomy X). In the mid 19th century, English physician rump Langdon cumulus studied children with mental retardation. cut down noniced that the children displayed a range of symptoms. What blast noniced 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. diarrhoetic with his findings Down did not pinpoint the cause of the syndrome. This happened well-nigh a century later. Why was there such a capacious gap between Downs initial findings and the baring of Trisomy 21? It was simply because at the time the technology did not exist to take note chr omosomes and karyotypes. In 1959 with the technology useable 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 entry a clear case of Trisomy X in 1959, victimisation 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 somewhat 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 privation to get a full essay, order it on our website: BestEssayCheap.com

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