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 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.

Size of expansion determines how the person is affected 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 ( 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.

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 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 mutation’s effects. 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.

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

Prognosis 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.

Treatments 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." 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

Resource s Fragile x syndrome. (n.d.). Retrieved from disorders/fragile-x-syndrome/ Fragile x syndrome. (2013, February 25). ¨ Retrieved from fragile-x-syndrome Fragile x syndrome. (2005, July). Retrieved from translations/english/11-fraxt.pdf