Developmental X-Linked

Fragile X Syndrome

The most common inherited cause of intellectual disability and autism spectrum disorder. More severe in males.

Genetic Information

Associated Gene

FMR1

Inheritance Pattern

X-Linked

Carrier Frequency

1 in 250 females, 1 in 800 males

Signs and Symptoms
  • Intellectual disability
  • Autism spectrum features
  • Long face, large ears
  • Hyperactivity and anxiety
Treatment and Management
Currently, only supportive care is available for this condition.

Educational support, behavioral therapy, symptom management

How Is It Inherited?

This condition follows an X-linked inheritance pattern. This means:

  • The gene is located on the X chromosome
  • Males are typically more severely affected (they have only one X)
  • Carrier females may have mild symptoms or be unaffected
Medical Reference

For detailed clinical information, visit the GeneReviews article:

GeneReviews: Fragile X Syndrome
Quick Facts
Category Developmental
Inheritance X-Linked
Gene(s) FMR1
Treatable No
Have Questions?

Speak with a board-certified genetic counselor to learn more about this condition and what it means for you.

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Disclaimer: This information is for educational purposes only and should not replace professional genetic counseling. If you have questions about genetic test results, please consult with a certified genetic counselor.