BIRTH DEFECTS

Down Syndrome (Trisomy 21)  
Down syndrome is a chromosomal disorder which causes physical and intellectual delays in development and occurs when there are 3 chromosome 21's, resulting in 47 total chromosomes instead of the normal 46. The most common clinical features are short neck and flat face, upward slanting eyes, low muscle tone and a single crease across the palm of the hand. Congenital heart defects accompany Down syndrome in about 40% of the cases. Vision and hearing problems are also common.

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