Fragile X Syndrome

  • Fragile X Syndrome
    • Second most common genetic cause of cognitive impairment after Down syndrome
      • 1 per 3600 boys
      • 1 per 4000 to 6000 girls
      • Caused by abnormal gene on the lower end of the long arm of the X chromosome
    • Clinical Manifestations
      • Physical Features
        • Increased head circumference
        • Long, wide, or protruding ears
        • Long, narrow face with prominent jaw
        • Strabismus
        • Mitral valve prolapse, aortic root dilation
        • Hypotonia
        • In postpubertal males, enlarged testicles
      • Behavioral Features
        • Mild to severe cognitive impairment (CI)
        • Speech delay; may be rapid speech with stuttering and word repetition
        • Short attention span, hyperactivity
        • Hypersensitivity to taste, sounds, touch
        • Intolerance to change in routine
        • Autistic-like behaviors, such as social anxiety and gaze aversion
        • Possible aggressive behavior
    • Therapeutic management
      • FXS has no cure. 
      • Medical treatment may include the use of serotonin agents, such as
        • To control violent temper outburst
          • Carbamazepine (Tegretol) 
          • Fluoxetine (Prozac)
        • The use of central nervous system stimulants or clonidine (Catapres) to improve attention span and decrease hyperactivity. 
      • Two possible treatments of FXS being investigated are reactivation of the affected gene and protein replacement
      • All affected children require referral to an early intervention program that requires
        • Interprofessional care 
          • Speech and language therapy
          • Occupational therapy
          • Special education assistance 
        • Interdisciplinary assessment
          • Cardiology
          • Neurology
          • Orthopedic anomalies
      • Prognosis
        • Individuals with FXS are expected to live a normal life span. 
        • Their CI may be improved by behavioral and educational interventions that usually begin in preschool-age children.
      • Care management
        • Since, the disorder is hereditary, genetic counseling is important to inform parents and siblings of the risks for transmission. 
          • Any male or female with unexplained or nonspecific mental impairment should be referred for genetic testing and, if needed, counseling