Fragile X Syndrome (FXS) represents the most common inherited cause of intellectual disability and autism, affecting approximately 1 in 4,000 to 6,000 individuals in the general population. About two-thirds of individuals with FXS have a form of autism spectrum disorder. FXS affects the X chromosome, specifically on the FMR1 gene; therefore, more males are diagnosed with FXS than females. Diagnosis of FXS is made through a DNA (blood) test. Cincinnati Children’s Fragile X Research and Treatment Center, led by Craig Erickson, MD, serves males and females of all ages affected by FXS.

Since there is no cure for FXS, treatment focuses on improving the quality of life for the patient and family, which includes management of symptoms. An interdisciplinary team at Cincinnati Children's has been developed to provide an individualized level of treatment for each patient. The Fragile X Research and Treatment Center provides educational materials, behavioral medication management, behavioral and cognitive assessment, and behavior therapy interventions. Referrals for other services including speech therapy, occupational therapy, special education consultation, and genetic counseling, can be made within Cincinnati Children's. 

Characterization / Symptoms of Full Mutation FXS

Physical and behavioral characteristics vary based upon the individual. Not all persons with FXS will have all characteristics.

Physical Characteristics

  • Long face
  • Prominent ears
  • Large testicles in males
  • Flat feet
  • Double-jointed fingers and hyper-flexible joints

Behavioral Characteristics

  • Gaze aversion
  • ADHD-like symptoms
  • Autism
  • Social anxiety
  • Hand-biting and/or flapping
  • Sensory disorders
  • Increased risk for aggression

Fragile X-associated Disorders

In addition to the full mutation of FXS, there are two known Fragile X-associated disorders (FXD), each thought to be caused by a change in the FMR1 gene.

Fragile X-associated Tremor / Ataxia Syndrome 

Fragile X-associated tremor / ataxia syndrome (FXTAS) is a neurodegenerative disorder, with an onset of 50 years of age or older. More males than females are affected. When females are affected, the symptoms are typically less severe. Symptoms of FXTAS include: balance problems, tremors, memory loss, personality change, and cognitive decline.

Fragile X-associated Primary Ovarian Insufficiency 

Fragile X-associated Primary Ovarian Insufficiency (FXPOI) is caused by a premutation in the FMR1 gene. FXPOI is characterized by ovarian dysfunction, which can lead to infertility and an early-onset menopause.