What is Down Syndrome?


The following information is from the National Institute of Child Health and Human Development (NICHD) Website.
For more information from the NICHD, go to www.nichd.nih.gov/ on the web.

Down Syndrome

Named after John Langdon Down, the first physician to identify the syndrome, Down syndrome is the most frequent genetic cause of mild to moderate mental retardation and associated medical problems and occurs in one out of 800 live births, in all races and economic groups. Down syndrome is a chromosomal disorder caused by an error in cell division that results in the presence of an additional third chromosome 21 or “trisomy 21.”

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