Fragile X and Autism

Fragile X syndrome can cause a child to have autism or an Autism Spectrum Disorder (ASD) though not all children with fragile X syndrome have autism or an ASD.

FACT:  For between 2% and 6% of all children diagnosed with autism, the cause is the Fragile X gene mutation.

FACT:  Approximately one-third of all children diagnosed with fragile X syndrome also have some degree of autism.

FACT:  Fragile X syndrome is the most common known single gene cause of autism.

If your child is diagnosed with autism, or an autism spectrum disorder (ASD), please ask the doctor to rule out fragile X syndrome by ordering the DNA blood test for Fragile X.

If your child is diagnosed with fragile X syndrome, and you believe your child also has autism or an Autism Spectrum Disorder, please consult with your child's doctor and ask that he or she be evaluated for autism or an ASD.

To learn more about the relationship between Fragile X and autism please visit: or call the National Fragile X Foundation at 1-800-688-8765.

From Dr. Randi Hagerman's statement to the United States House of Representatives Subcommittee on Health and Environment:

"...Fragile X represents a portal through which we hope to view and treat a wide variety of other disorders of brain development and function. All children with autism...should be tested for Fragile X."