Fragile X Syndrome in Children

Fragile X syndrome is the most common cause of inherited intellectual disability (mental retardation).

Remarkable Care for Kids

  • Unique in Chicago: The Fragile X Clinic at Rush offers comprehensive care, family counseling and diagnosis of fragile X syndrome. This is the only fragile X clinic in Chicago.
  • Comprehensive specialty care: At Rush, your child will receive comprehensive care for fragile X syndrome from a multidisciplinary care team that may include specialists in pediatric neurologygeneticschild psychology, speech therapy, occupational therapy and physical therapy.
  • Genetic testing and counseling: The Section of Genetics at Rush provides genetic counseling, testing and support for families facing fragile X syndrome. Genetics specialists at Rush University Children’s Hospital have international reputations for their contributions to genetics research, including fragile X.
  • Leaders in research and development: Clinician-researchers in the Fragile X Research and Fragile X-Associated Disorders Programs at Rush are leaders in researching and developing new treatments for fragile X.

What is fragile X syndrome?

Fragile X syndrome is a genetic disorder caused by a mutation on the X chromosome that affects brain development and function. It is the most common known genetic cause of autism, but not everyone with fragile X has autism.

Fragile X causes behavioral and emotional problems, along with intellectual impairment.

Fragile X symptoms are typically less severe in girls than boys. Boys tend to have more serious intellectual disability and more behavior problems than girls. Girls with fragile X may have normal intelligence and learning disabilities, social and emotional problems, anxiety and/or attention problems — or they may have no problems.

Symptoms of fragile X syndrome

Talk to your pediatrician if your child has any of these fragile X symptoms:

  • Developmental delays: Not sitting, walking or talking at the same time as other children their age
  • Learning disabilities: Trouble learning new skills
  • Social and behavioral problems: Not making eye contact, anxiety, hand flapping, trouble paying attention
  • Communication challenges: Difficulty talking to and interacting with other

Having these symptoms does not mean your child has fragile X syndrome. Many other conditions have similar symptoms. Your doctor at Rush can help you determine the root of your child’s problem.

Care for fragile X syndrome at Rush


A DNA blood test can diagnose fragile X syndrome in children of all ages. Early diagnosis allows your child to get early intervention and therapies that can help improve the symptoms of fragile X.


While there is no cure for fragile X syndrome, Rush offers — or can refer you to— a wide range of treatments and services to help children with fragile X reach their full potential.

  • Medications can help manage neurological issues (e.g., seizures) and behavioral challenges.
  • Educational recommendations can help you create the most effective learning environment and strategies for your child.
  • Speech therapy helps your child improve pronunciation and use language effectively.
  • Occupational therapy helps your child learn how to complete day-to-day tasks.
  • Physical therapy uses activities and exercises to improve your child’s motor skills, posture and balance.
  • Behavioral therapy teaches you and your child how to cope with behavioral challenges of fragile X.
stethoscope Meet our fragile X syndrome providers