Fragile X

Brianna Stobbe3/6/13

Period 4

Common and scientific name: fragile X syndrome (FXS)

Other names: Martin-Bell syndrome,Marker X syndrome, FRAXA syndrome

Name

Cause

Inherited, but not expressed in every generation.

Premutation: repetition of CCG sequence in DNA of X chromosome more than 50 times. Does not cause syndrome, but may cause it in children.

Full mutation: repetition of CCG sequence more than 230 times, which disables the FMR-1(fragile X mental retardation) gene and causes syndrome

Every ethnicity

1 in 1,250 males1 in 2,000 females

Males have one X chromosome, while females have two. Females are less likely to have the syndrome because the FMR-1 gene is active on the other chromosome. Symptoms of females are generally mild.

Target Population

The FMR-1 gene codes for a protein that helps develop synapses, the connections between nerve cells. When the the FMR-1 gene is disabled, neurotransmitters are not relayed correctly.

CNS/PNS

developmental delaysmental retardationautismattention deficit disorder

(ADD)digestive disordersheart conditionsseizureslarge earslong, narrow face

Symptoms

Genetic test for mutation or premutationAmniocentesisChorionic villus samplingpercutaneous umbilical blood sampling

Prognosis

No present cure. Gene therapy may be an option in the future.

Drugs can treat ADD and seizures.

Speech and language therapy and special education teachers may be needed.

Cure/Treatment

Albert Einstein had Asperger syndrome, a type of autism, that was likely caused by fragile X.

James Denton from Desperate Housewives has been a supporter of the cause.

Notable Cases/Supporters

OrganizationsNational Fragile X

Foundation and FRAXA Research Foundation fund scientific research, support families affected, and raise awareness.

Sex chromosome abnormalities. (2007). In World of Health. Gale. Retrieved from http://ic.galegroup.com/ic/suic/ReferenceDetailsPage/ReferenceDetailsWindow?query=&prodId=SUIC&displayGroupName=Reference&limiter=&source=&disableHighlighting=false&displayGroups=&sortBy=&search_within_results=&action=2&catId=&activityType=&documentId=GALE%7CCV2191501165&userGroupName=cary81451&jsid=5136b759afdd4ff30ffe0f0d2cbb26e8

Quercia, N. (2005). Fragile X Syndrome. In B. Narins (Ed.), The Gale Encyclopedia of Genetic Disorders (2nd ed., Vol. 1, pp. 472-475). Detroit: Gale. Retrieved from http://go.galegroup.com/ps/i.do?id=GALE%7CCX3451500155&v=2.1&u=cary81451&it=r&p=GPS&sw=w

Works Cited