Fragile X Syndrome
- Fragile X syndrome facts*
- What is Fragile X syndrome?
- What causes Fragile X syndrome?
- What keeps the FMR1 gene from producing FMRP in Fragile X syndrome?
- Human cells 101
- How many people are affected by Fragile X syndrome?
- How is Fragile X syndrome inherited?
- What are the signs and symptoms of Fragile X syndrome?
- Intelligence and learning
- Social and emotional
- Speech and language
- Is there a cure for Fragile X syndrome?
- Are there treatments for Fragile X syndrome?
- Educational options
- Therapeutic options
- Medication options
- What are the options for adults who have Fragile X syndrome?
- What should I do if I find out someone in my family has Fragile X syndrome?
- What is being done to develop treatments or a cure for Fragile X syndrome?
- Where can I go for more information about Fragile X syndrome?
- Patient Comments: Fragile X Syndrome - Experience
Fragile X syndrome facts*
*Fragile X syndrome facts medical author: Charles Patrick Davis, MD, PhD
- Fragile X syndrome (also called Fragile X) is the most common inherited form of mental problems (mental retardation).
- Fragile X syndrome is caused by changes in a single X chromosome (FMR1).
- FMR1 does not produce enough protein (FMRP) that works cell communication.
- Normal X genes that control FMR1 levels have promoter regions consisting of about 6 to 40 CGG; Fragile X genes have about 55 to 200 (termed premutation) or more than about 200 regions (termed full mutation).
- About 100 trillion cells make up a human body and each should have 46 chromosomes, but males have only one X chromosome; so, if it contains a FMR1 chromosome, the effect of the lack of FMRP is more significant than in females.
- Approximately one in 3,600 to 4,000 males is affected by the full mutation of the FMR1 gene, and about one in 468 males has the premutation form of the FMR1 gene; about one in 151 females in the general population has the premutation while about one in 4,000 to 6,000 females is affected by the full mutation (these are estimates only).
- The Fragile X gene is only carried on an X chromosome; both males and females may transmit a Fragile X (FMR1) gene on their X chromosome.
- The signs and symptoms of Fragile X syndrome have five general categories where individuals often show altered or arrested development: intelligence and learning (low IQs); physical (long face or jaw, short stature, enlarged testicles); social and emotional (anxiety); speech and language (stuttering and disorganized speech); and sensory (sensitive to certain stimuli like sounds, balance problems). Each individual may exhibit variations in these categories.
- Currently, there is no cure for Fragile X syndrome nor are there any definitive treatments other than helping the individual develop to their maximal potential through education; therapies such as speech, language, behavioral, and physical; and other therapies.
- Medication therapy may only help certain individuals with certain severe problems and should be prescribed only by the patients' doctors; there is no medication that can cure Fragile X syndrome.
- Adults with Fragile X syndrome may benefit from a team approach to help the patient adjust to independent living, if possible.
- If a family member has been diagnosed with Fragile X syndrome, other family members may want to be tested to determine if they carry a Fragile X chromosome; there are several accurate DNA tests available for gene testing and for quantizing the amount of FMRP produced. Prenatal tests are also available.
- Research is ongoing; gene therapy, gene activation, and FMRP replacement therapy are several areas that may lead to treatments, or possible cure or prevention, in the future.
- Several national organizations may provide additional information on Fragile X syndrome (for example, American Association on Mental Retardation and the National Institute of Child Health and Human Development).
Medically Reviewed by a Doctor on 4/4/2014
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Fragile X Syndrome - Symptoms Question: What symptoms do you or your loved one experience from fragile X syndrome? How do you cope?
Fragile X Syndrome - Carrier Question: Did you ever undergo genetic testing to see if you are a fragile X syndrome carrier?
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Fragile X Syndrome - Social and Emotional Issues Question: How does your child with Fragile X deal with social situations? Please share how you cope with your child's emotional issues.
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