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.
The risk of this problem is higher in people who have a family history of the faulty FMR1 gene.
Problems are different from person to person. They happen less often and are mild in females. Problems may be:
Behavioral problems, such as:
Being very sensitive to loud noises or bright lights
Extreme shyness, especially in girls
Physical problems, such as:
A long face with a jaw that sticks out
Joints that bend past normal limits
A high-pitched voice and enlarged testes in males after puberty
Problems with motor skills like sitting and walking
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.
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
Speech, occupational, physical, or behavioral therapy
Special education services to help with learning
There are no known guidelines to prevent this health problem.
Fragile X syndrome. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/fragile-x-syndrome. Accessed November 4, 2020.
Fragile X syndrome overview. National Institute of Child Health and Human Development website. Available at: http://www.nichd.nih.gov/health/topics/fragilex/Pages/default.aspx. Accessed November 4, 2020.
Lozano R, Azarang A, et al. Fragile X syndrome: A review of clinical management. Intractable Rare Dis Res. 2016 Aug;5(3):145-157.
What is fragile X? FRAXA Research Foundation website. Available at: http://www.fraxa.org/fragilex. Accessed November 4, 2020.
Last reviewed September 2020 by EBSCO Medical Review Board
Kari Kassir, MD
Last Updated: 5/11/2021
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