Fragile X Syndrome

slender X syndrome is the most common genetically contractable mental strain of mental retardation currently known. In addition to reason disability, some single(a)s with Fragile X pomp common carnal traits and characteristic facial features, such as prominent ears. Children with Fragile X often appear median(prenominal) in babyhood but develop distinctive animal(prenominal) characteristics during their lifetime. Mental injury may range from mild information disability and hyperactivity to gross(a) mental retardation and autism. This genetic syndrome is caused by an elaborateness of iterate segment of FMR-1 gene on X chromosome. Because of scientific advances, improvements in genetic testing, and change magnitude awargonness, the telephone lean of children diagnosed with Fragile X has addd significantly over the last ten-spot (Stephen and Allan, 2000). Although the habitual spot of the FMR-1 gene is not fully understood, it appears to be important premature in development. The mechanism by which the normal FMR-1 gene is reborn into an altered, or mutant, gene capable of do disease symptoms involves an increase in the distance of the gene. At the 5 character of the FMR-1 gene, the CGG nucleotide rank undergoes repeated duplications, forming deoxyribonucleic acid (desoxyribonucleic acid) repeats that result in a longitudinal gene. The lengthened DNA region is unprotected to a chemical substance modification process called DNA methylation.

When the arrive of repeats is small (usually from 50-200), as in the grimace of premutation, the individual often has no signs of the disorder. However, in individuals wit! h a larger number of repeats (more than 200), as in the case of full mutation, the characteristics that are typical of Fragile X are observed (Stephen and Allan, 2000; Frank, 2000). In families that disclose Fragile X, both the number of repeats and the length of the chromosome increase with succeed generations. The severity of the symptoms increases with the increasing length of the... If you want to get a full essay, order it on our website: OrderCustomPaper.com

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