FRAGILE X SYNDROME

WHAT IS FRAGILE X SYNDROME?

The karyotype occurs in the X chromosome. People with fragile X syndrome have

a “broken” X chromosome that appears to have a pre-split area. The chromosome is not actually broken but appears damaged and glued. Females can carry the

chromosome but will appear normal due to their second X chromosome. This disorder appears mostly in males. People who have this condition are

mentally retarded, short, and have very large heads with-long and narrow faces. Some people have large and prominent ears.

A change in a gene that is inherited at the time of conception. This gene, called the

FMR1 gene is found on the X chromosome. When this gene change occurs the FMR1 gene does not work properly. The FMR1 gene is responsible for making a protein that is important in brain development. Therefore when the gene is not working

properly brain function is affected.

HOW DOES FRAGILE X SYNDROME OCCUR?

Can it be passed to future generations?

Fragile X can be passed on in a family by individuals who have no apparent signs of this genetic condition. In some families a number of family members appear to be

affected, whereas in other families a newly diagnosed individual may be the first family member to exhibit symptoms. 

HISTORY!1910 Thomas Hunt Morgan demonstrates that when a gene is located on the X chromosome of the fruit fly, the characteristic appears more frequently in males than in females.

In 1943, Martin and Bell showed that a particular form of mental retardation (later known as fragile X syndrome) was X-linked.

In 1969, Herbert Lubs developed the chromosomal test for Fragile X and finds visual proof of the linkage of mental retardation and the X chromosome.

In 1991 the FMR1 gene that causes Fragile X was identified. 

 

Type?

Occurs due to an unstable gene that mutates frequently in human beings. The type of

mutation involved, known as a “trinucleotide repeat disorder,” involves multiple errors in the genetic code that make up the affected gene.

Gene mutation

Diagnosis

Fragile X syndrome is diagnosed based upon developmental delays, behavioral characteristics, and physical traits. Your doctor will ask about

any family history of mental retardation. To make a definite diagnosis, a drop of blood taken from a finger can be analyzed for the fragile X gene. If a woman

is pregnant and she is a carrier, or there is a history of fragile X syndrome in the family, there are procedures that can be performed during the pregnancy to look

for fragile X syndrome.

Treatment

There is no cure for fragile X syndrome, but it can be treated through speech and language therapy, occupational therapy,

physical therapy, and psychotherapy. Drugs may be used to treat behavioral problems, such as mood swings and

aggressive outbursts. Children with fragile X syndrome usually follow a regular

routine and avoiding over-stimulation and distractions.

Bibliographyhttp://www.hmc.psu.edu/childrens/healthinfo/f/fragilex.htm

www.marchofdimes.com. N.p., n.d. Web. 4 Nov. 2009.      <http://www.marchofdimes.com/pnhec/4439_9266.asp>.

http://www.nfxf.org. N.p., n.d. Web. 4 Nov. 2009. <http://www.nfxf.org/html/      cause.htm>.

http://www.hmc.psu.edu. N.p., n.d. Web. 4 Nov. 2009. <http://www.hmc.psu.edu/      childrens/healthinfo/f/fragilex.htm>.

fregilex. N.p., n.d. Web. 4 Nov. 2009. <http://www.fragilex.org/html/