Fragile X Syndrome

slender X syndrome is the most common genetically communicable mental strain of mental retardation currently known. In addition to reason disability, some respective(prenominal)s with Fragile X display common carnal traits and characteristic facial features, such as prominent ears. Children with Fragile X often appear prevalent in babyhood but develop emblematic physical characteristics during their lifetime. Mental injury may range from mild learnedness disability and hyperactivity to gross(a) mental retardation and autism. This genetic syndrome is caused by an enlargement 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 tenner (Stephen and Allan, 2000). Although the modal(prenominal) spot of the FMR-1 gene is not fully understood, it appears to be important premature i n development. The mechanism by which the normal FMR-1 gene is reborn into an altered, or mutant, gene capable of cause disease symptoms involves an increase in the distance of the gene. At the 5 parting 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 suasible to a chemical substance modification process called DNA methylation. When the consequence 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 with 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 certify Fragile X, both the number of repeats and the length of the chromosome increase with come through generations. The s everity of the symptoms increases with the i! ncreasing length of the... If you want to get a full essay, order it on our website: OrderCustomPaper.com

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