Fragile X Syndrome (FXS)
Fragile X syndrome (FXS) is one of the most common causes 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.
Mythbusters
![Mythbusters Think you know fragile X? Guess again.](https://webarchive.library.unt.edu/web/20210120084233im_/https://www.cdc.gov/ncbddd/fxs/images/FXS-mythbusters-343x196px.jpg)
Think you know fragile X? Guess again.
Video: Cause of Fragile X
Watch this video to learn about the causes of Fragile X Syndrome.
How Fragile X Is Inherited
![How Fragile X Is Inherited Human chromosomes, illustration](https://webarchive.library.unt.edu/web/20210120084233im_/https://www.cdc.gov/ncbddd/fxs/images/chromosone-illustration-343px.jpg)
Researchers at CDC are working to better understand how this complex condition affects individuals and their families.
Page last reviewed: October 23, 2020