Definition

Fragile X syndrome (FXS) is a genetic problem that results in intellectual disability.

Cognitive Mapping of the Brain

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Causes

FXS is inherited from parents. It is caused by problems with the FMR1 gene. These problems stop the fragile X mental retardation protein (FMRP) from developing. This protein is needed to make connections in the brain.

Risk Factors

The risk of this problem is higher in people who have a family history of the faulty FMR1 gene.

Symptoms

Problems are different from person to person. They happen less often and are mild in females. Problems may be:

• Learning problems
• Slowed development
• Speech problems
• Behavioral problems, such as:
  • Mood swings
  • Outbursts
  • Being very sensitive to loud noises or bright lights
  • Aggression
  • Extreme shyness, especially in girls
• Physical problems, such as:
  • A long face with a jaw that sticks out
  • Large ears
  • Flat feet
  • Joints that bend past normal limits
  • A high-pitched voice and enlarged testes in males after puberty
  • Floppy muscles
  • Problems with motor skills like sitting and walking

Diagnosis

The doctor will ask about your child's symptoms and health history. A physical exam will be done.

The diagnosis can be confirmed with a genetic test.

Treatment

There is no cure for FXS. The goal is to manage symptoms. Choices are:

• Medicines, such as:
  • Stimulants to treat attention and behavior problems
  • Medicine to control mental health problems
  • Antiseizure medicines
• Speech, occupational, physical, or behavioral therapy
• Special education services to help with learning

Prevention

There are no known guidelines to prevent this health problem.