G08: Science Genetic Disorders: Fragile X syndrome

Little known until a new technique facilitated identification in the 1980s, Fragile X, or fra(X), is the most common heritable cause of mental retardation (MR). Fra(X) owes to a weak site on the X chromosome, is sex-linked, and is largely responsible for higher prevalence of MR in males than females. Discovery of the responsible gene has led to replacement of cytogenetic tests with more effective and less expensive DNA ones, which identify affected individuals and carriers

Fragile X syndrome (FXS) is caused by a mutation of a single gene — FMR1 — on the X chromosome and is inherited genetically, often unknowingly. Everyone has the FMR1 gene on their X chromosome, but when a mutation occurs, it can cause intellectual disability, behavioral and learning challenges, and various physical characteristics. There is no cure, but therapies, interventions, and medications are often prescribed to treat behavioral symptoms like anxiety, aggression, and ADHD.

Fragile X syndrome is a genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment. Usually, males are more severely affected by this disorder than females.
Affected individuals usually have delayed development of speech and language by age 2. Most males with fragile X syndrome have mild to moderate intellectual disability, while about one-third of affected females are intellectually disabled.

Fragile X syndrome is the most common inherited intellectual and developmental disability. Up to 1.5 million Americans have the gene premutation, and up to 100,000 Americans have Fragile X syndrome.​

The National Fragile X Foundation serves all those living with Fragile X with a focus on Advocacy, Education, Research, and Treatment with Community at the heart of everything we do.