Fragile X Syndrome is an x-linked trait and the second most common identifiable cause of genetic mental retardation after Down syndrome (Wyndbrandt & Ludman, 2008). It is a very unpredictable and unpreventable disorder which not only touches those who suffer from it, but those around them as well. Its affect, is sometimes devastating. When analyzing Fragile X Syndrome it is crucial to examine its inheritance pattern, the genetic mutation which causes the disease, the signs and symptoms of the disorder.
Foremost, Fragile X Syndrome is caused by a break of weakness on the long arm of the X chromosome. It can be traced back to a mutation in a gene called the FMR-1 gene. With Fragile X, the FMR-1 gene is much bigger than normal where the CGG is repeated. The average number of repeats is 30 for a normal person. A carrier of fragile X will usually have 50-200 repeats. A person with Fragile X has 200 or more repeats. A person with Fragile X has a “full mutation”. When there are so many repeats in the gene, methyl groups attach to the cytosine and turn the gene off. The gene then cannot produce any FMRP (Fragile X Mental Retardation Protein). If a person doesn’t have the protein, they can develop mental impairment and other characteristics (Alanay, 2007).
Fragile X is estimated to occur in 1 in 1,200 males and 1 in 2,500 in females. It occurs in all racial, ethnic, and socioeconomic groups. It is the most common genetic disease and is the most commonly inherited cause of learning disabilities and mental retardation, accounting for approximately 40 percent of cases with X-linked mental retardation. A screening study in a U.S. public special education population suggests that approximately 1 in 400 males receiving special education services are affected the Fragile X syndrome (Crawford, 2001). Although the Fragile X Syndrome occurs in both male and females, females have usually milder symptoms.
Furthermore, when discussing Fragile X Syndrome, it becomes...