Julia Brown

3/6/13

3rd Period

Other Common Names:

Martin-Bell Syndrome

Escalante’s Syndrome

FXS

- Fragile X Syndrome is caused by an abnormality in the FMR1 gene, located on the X

chromosome.

The abnormality is an expansion of that gene. Anexpansion is when part of the gene is repeated

when itis not supposed to be.

The size of the expansion determines ifthe person is only a carrier (meaning they just have

the premutation) or ifthey show signs of the disorder.

Size of expansion determines how the person

is affectedThis represents an X chromosome with a normal fragile X gene (unexpanded - up to 60 repeats is considered normal)

An X chromosome with a small expansion of the fragile X gene (60-200 repeats) A person with this chromosome is a carrier and has the premutation.

This X chromosome has a large expansion (over 200 repeats) and is considered a full mutation.

Since both males and females have an Xchromosome, either parent can pass this condition

to their children.

However, the gene is usually passed from mother to son.

Target Population

If a female has the expansion on the FMR1 gene,she is less likely to be affected because her 2nd X

chromosome can potentially balance out theeffects of the mutated gene.

If a male has the expanded FMR1 gene, the Ychromosome has no way to counter any of the

mutation’s effects.

1 in 4,000 males affected1 in 8,000 females affected

Since the daughters have a 2nd X chromosome, they are less likely to show effects of Fragile X.

Along with being more likely to get it, males are affected more

seriously than females are.

This results

in a failure

to produce

the FMRI1 protien

.

The actual cause of the symptoms of fragile X is when the abnormally expanded gene causes it to turn off.

This failure to produce

the FMR1 protein disrupts

the nervous system

functions

The nervous system deals a lot with •interpreting sensory information,•thinking•perceiving•understanding language

Fragile X syndrome mostly affects the central nervous system, as all of the above are affected by it.

People with fragile x often have cognitive disabilites and developmental delays, which all deal with the

nervous system.

Symptoms• Intellectual disabilities - ranging from mild learning

problems to retardation• ADHD• Anxiety• Unstable mood• Autism or autistic behaviors• hypersensitivity to bright lights or loud sounds• Lanugage problems• Epilepsy (affects 25% of people with fragile x)• Emotional and behavioral problems

Physical Symptoms• Long face• large ears• flat feet• low muscle tone• hyperextensible joints

PrognosisIt is best if fragile x is diagnosed early on. This way the affected child can receive the proper special care when it comes to education and development.

People with with fragile x are expected to live normal life spans.

TreatmentsThere are no specific treatments, but rather proper guidance, training, and

education can help those affected function as well as possible.

Special treatment centers and

organizations:

"FRAXA's mission is to accelerate progress toward effective treatments and ultimately a cure for Fragile X, by directly funding the most promising research."

• Founded in 1994• Helps by funding grants at

universities• Runs mainly on volunteers• Work to find a cure and to

raise awareness

Fragile X Research and Treatment Center

•At UC Davis and University of Washington in Seattle

•Funded by the National Institutes of Child Health and Development (NICHD)

•Studies individuals with fragile x from birth to adulthood

Resources Fragile x syndrome. (n.d.). Retrieved from

http://www.fragilex.org/fragile-x-associated-disorders/fragile-x-syndrome/

Fragile x syndrome. (2013, February 25).

¨

Retrieved from http://ghr.nlm.nih.gov/condition/fragile-x-syndrome

Fragile x syndrome. (2005, July). Retrievedfrom http://www.geneticalliance.org.uk/docs/

translations/english/11-fraxt.pdf