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Fragile X syndrome (FXS) is the most common known cause of inherited intellectual disability. CDC is working to learn more about fragile X syndrome and fragile X-associated disorders to improve the health and well-being of people with these conditions.

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How can my child have fragile X syndrome? It’s not in our family. Learn how FXS can happen anyway.

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Real stories from people living with fragile X syndrome.

Fragile X Syndrome Video


Learn about the causes of fragile X syndrome.

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Researchers at CDC are working to better understand how this complex condition affects individuals and their families.