Julia Brown 3/6/13 3rd Period. Other Common Names:. FXS Martin-Bell Syndrome Escalante’s Syndrome. - 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. An
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- Fragile X Syndrome is caused by an abnormality in the FMR1 gene, located on the X
The abnormality is an expansion of that gene. An
expansion is when part of the gene is repeated when it
is not supposed to be.
The size of the expansion determines if
the person is only a carrier (meaning they just have the premutation) or if
they show signs of the disorder.
This 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 X
chromosome, either parent can pass this condition
to their children.
However, the gene is usually passed from mother to son.
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 the
effects of the mutated gene.
If a male has the expanded FMR1 gene, the Y
chromosome has no way to counter any of the
1 in 4,000 males affected
1 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.
The actual cause of the symptoms of fragile X is when the abnormally expanded gene causes it to turn off.
This results in a failure to produce the FMRI1 protien.
This failure to produce the FMR1 protein disrupts the nervous system functions
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.
It 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.
There 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."
Fragile x syndrome. (n.d.). Retrieved from
Fragile x syndrome. (2013, February 25).
Retrieved from http://ghr.nlm.nih.gov/condition/
Fragile x syndrome. (2005, July). Retrieved