Genetics To Down Syndrome

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Genetics To Down Syndrome
Genetics describes the makeup of our cells, genes, chromosomes, and phenotypes. When there is alter in a gene or a duplication of a chromosome, it can lead to a certain diseases. One of the main diseases known today from a duplication of a chromosome is Down syndrome. John Down first put a name to Down syndrome in 1866, but artifacts from Mexico and Saxon documented some cases of Down syndrome in individuals, and also some were found in paintings of the Renaissance in Europe. (Fisher & Hernandez, 1996) Not till 1959 though did we learn that Trisomy 21 was the known cause of Down syndrome with the presence of 3 copies of chromosome 21. (Bléhaut et all, 2007)1 in every 600 individuals born in the Unites States are diagnosed
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Gene expression happens when cell’s DNA wraps around cluster of a globular histone proteins to form nucleosomes. Nucleosomes and histone are put together to make chromatin. When the structure of chromatin changes, it affects gene expression. This leads to epigenetics patterns of DNA methylation and histone modifications. Alternations of these patterns cause change in the regulation of gene expression. After these changes in gene expression, the results are an epigenetic cause of disease because of the loss of normal DNA methylation. (Mann & Rodenhiser, …show more content…
These phenotypes have many clinical features that include cognitive impairments, muscle hypotonia, short stature, facial dysmorphisms, congenital and heart disease. (Bléhaut et all, 2007) Other features also include congenital anomalles of the gastrointestinal tract, increase risk for leukemia, immune system defects, and Alzheimer- like dementia. (Caprenter et all, 1994) According to Carpenter and his other colleges, A phenotype is a “measurable parameter and it includes clinical, physical, cellular, and physiological components”. Bèlhaut also stated that “phenotypic mapping the molecular definition of a physical region that is likely to contain the gene or genes whose overexpression is ultimately responsible in part for the phenotype”. When they discovered that trisomy for chromosomes arms help show phenotypes, they decided to use partial trisomy to help navigate the diverse symptoms in an individual. This showed that the regions might contain the genes responsible for some of the many features of Down syndrome. This gave them the information to create a Down syndrome phenotypic map. When making these phenotype or physical maps of chromosome 21, we can possibly understand the genetic basis of some of these features or defects and can slowly learn how to prevent, ameoliorate, and eliminate their treatment. These maps also help provide the basis for clinical prognosis for people who have partial aneuploidy for chromosome 21, and also

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