Down's Syndrome: Causes & Symptoms ||Class 12 Biology

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   Down's Syndrome was described by J Langdon Down in 1866. It also known as Trisomy-21, Mongolian idiocy, Mongolism. Down's Syndrome is genetic disorder. It occurs due to the presence of an additional copy of chromosome number 21 in humans.
    Down's Syndrome is the most common chromosome abnormality in humans. It occurs in about 1 in 1000 babies born each year. 
    Affected individuals are short statured with small round head, furrowed tongue and partially open mouth. Palm is broad with characteristic palm crease. Physical, psychomotor and mental development is retarded. 
    There is no cure for Down's Syndrome. Education and proper care have been shown to improve quality of life.





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