Fragile X Syndrome Is Caused

Fragile X Syndrome is caused by a genetic mutation in the FMR1 gene. The condition is present at birth but does not always manifest in noticeable symptoms until the individual is slightly older and then begins to lag behind in developmental processes. Fragile X Syndrome is actually the most common cause of inherited metal impairment. It is also clear that this impairment can range in severity from simple learning disabilities to severe cognitive or functional intellectual disabilities. "FXS is the most common known cause of autism or "autistic-like" behaviors. Symptoms also can include characteristic physical and behavioral features and delays in speech and language development." (National Fragile X Foundation (NFXF) Website, 2007, NP)

Fragile X syndrome is often called the most prevalent inherited cause of mental retardation. The disorder is caused by a single gene disorder on the X chromosome.

The syndrome results from an expansion of three nucleotides (CGG) on the FMR-1 gene preventing the production of FMR protein, which is assumed to be essential for normal brain development...The behavioral consequences associated with the loss of protein because of the "turned off" gene are profound, affecting overall development..., patterns of behavior..., and physical features. In addition, the effects are different for males and females..., such that males are more severely affected. (Symons, Clark, Roberts & Bailey, 2001, p. 194)

Variation in severity of symptoms is seen and as is stated above affects males more than females. It is for this reason that much of the research associated with behavior and designed for intervention surrounds male children. In one study associated with the classroom behavior of male children with FXS the boys were in need of assistance with engagement in classroom learning activities and that most do better in special education classrooms as they offer more opportunity for direct (one on one) instruction;

Overall. results suggest that students with FXS were moderately engaged in classroom activities during periods of instruction in self-contained special education classrooms and more inclusive settings. They tended to be engaged with academic materials or some combination of materials with either peers or adults. The students with FXS had similar levels of engagement during different instructional arrangements and were similarly engaged regardless of autism status, general delays in adaptive behavior, or medication statue and age. In addition. measures of classroom quality correlated significantly with levels of engagement for both students with FXS and their peers. This finding supports the acknowledged importance of environmental arrangements in relation to overall levels of engagement and is generally consistent with results from previous research for students with other disabilities. (Symons, Clark, Roberts & Bailey, 2001, p. 194)

Classroom engagement demonstrates, among all disabilities, one of the most important factors in future academic capabilities. (Symons, Clark, Roberts & Bailey, 2001, p. 194) Children affected with FXS need additional classroom and behavioral support, in much the same way that high and low level functioning autistic children need assistance.

The fragile X mutation can also cause two less severe patterns of disorders that cause carriers to be affected, depending on gender. Older male carriers can exhibit fragile X-associated tremor/ataxia syndrome, which can seriously effect balance, memory and cause a demonstrative tremor, while in women is can cause fragile X-associated primary ovarian insufficiency which can in some women lead to infertility and very premature menopause. Neither of these carrier associated diseases are necessary for a carrier to have the necessary gene disparity that creates the mutation that causes Fragile X syndrome. Carriers can be completely asymptomatic and there may be no known historical case in a family or several members of the same family can exhibit symptoms of Fragile X disorders. (National Fragile X Foundation (NFXF) Website, 2007, NP) This is the reason that genetic counseling is an essential element of the disease diagnosis as well as with regard to future fertility issues. (Strom, 1990, p. 52)