Down Syndrome

Down syndrome is a set of cognitive and physical symptoms that result from having an extra chromosome 21 or an extra piece of that chromosome. It is the most common chromosomal cause of mild to moderate intellectual disabilities. People with Down syndrome are at risk for several other health conditions.

Understanding Down syndrome and other intellectual and developmental disabilities is part of the reason NICHD was established. Today, the institute continues to lead research on the causes, progression, treatment, and management of Down syndrome, as well as on conditions and diseases that are associated with the syndrome.

Alternate Titles
Trisomy 21
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