Fragile X syndrome (FXS) is a genetic condition that causes intellectual disability, behavioral and learning challenges, and various physical characteristics.   As many as 1 in 130 women are carriers of the Fragile X mutation. Estimates vary and studies are ongoing.

Fragile X Syndrome is  the leading known genetic cause of autism. Among the total population of those with autism, approximately 2-6% are diagnosed with Fragile X Syndrome as the underlying genetic cause.  Approximately two thirds of all children with Fragile X Syndrome also have autism, an autism spectrum disorder or behaviors associated with autism.

 Over one-million Americans carry a Fragile X mutation or are at risk for developing, a Fragile X-associated Disorder, including FXTAS (Fragile X-Associated Tremor Ataxis Syndrome) and FXPOI (Fragile X-Associated Primary Ovarian Insufficiency).

 Over 100,000 Americans have Fragile X Syndrome, making FXS the leading cause of inherited intellectual disability.