What is Fragile X Syndrome?
Fragile X syndrome is a genetic condition caused by a mutation (CGG repeat expansion) in the FMR1 gene on the X chromosome. This mutation leads to a lack of production or a reduction of the fragile X mental retardation protein (FMRP), which is essential for normal brain development. It is the most common inherited cause of intellectual disability and autism spectrum disorder. The condition follows an X-linked dominant inheritance pattern, meaning it can affect both males and females, but symptoms are often more severe in males.
Key Features
- Most common inherited cause of intellectual disability
- More severe effects in males than in females
- Can cause learning disabilities, behavioral challenges, and developmental delays
- Associated with certain physical features
Common Symptoms
- Delayed speech and language development
- Intellectual disability ranging from mild to severe
- Behavioral issues such as anxiety, hyperactivity, and social difficulties
- Autism spectrum disorder traits
- Long face, large ears, and flexible joints in some individuals
How to Reduce the Risk
Genetic counseling to understand inheritance patterns and reproductive options
Carrier screening for individuals with a family history of Fragile X syndrome or unexplained intellectual disabilities
Preimplantation Genetic Testing for Monogenic Disorders (PGT-M) during IVF to select embryos without the FMR1 mutation
Prenatal genetic testing for early detection during pregnancy