Fragile X Syndrome: The Most Common Inherited Cause of Cognitive Impairment

What is Fragile X Syndrome?
Fragile X syndrome is the most common inherited cause of cognitive impairment and the most common known cause of autism. The Centers for Disease Control estimates that about 1 in 4,000 males and 1 in 6,000 to 8,000 females have fragile X syndrome. While the severity and characteristics vary, fragile X syndrome affects all ethnic and socioeconomic groups.

Individuals with FXS may exhibit a number of symptoms including autistic behaviors, attention deficit and hyperactivity, anxiety, cognitive impairment, and seizures (in 25% of the population).

FXS typically impacts boys more severely than girls. Most males with the disorder have severe intellectual disability. Emotional and behavioral issues are common for both genders.

The Cause of Fragile X Syndrome
Fragile X Syndrome is caused by a mutation of FMR1, a single gene located on the X chromosome. The mutated FMR1 gene is silenced, blocking expression of the fragile X mental retardation protein (FMRP) that is needed for normal brain development.

Fragile X Treatment A variety of medications and behavioral interventions are used to alleviate individual symptoms. Currently, there are no treatments that target the underlying cause of the disorder.