Fragile X syndrome is the most commonly known cause of inherited developmental disability. It is estimated that it occurs one in every 2000 - 5000 live births. Fragile X is caused by mutations in a gene on part of the X chromosome, which leads to abnormal brain development. This disability also accounts for six - ten percent of unexplained cases of mild mental retardation.
Persons with Fragile X syndrome can have a wide variety of impairments. The cognitive impairments can range from mild learning disabilities to severe mental retardation. Sometimes there are also other behavioral problems, such as hyperactivity and impulsivity problems, and social anxiety. Frequently those with Fragile X also have physical abnormalities, such as a long narrow face, large ears, and a prominent forehead and jaw. Girls who are affected tend to have a broader range of deficits. They tend to function higher intellectually than do the males with the disorder. Nearly all of the males with Fragile X have some type of cognitive abnormality. Some experts have said that approximately one-third are in the mentally retarded spectrum.
There have also been some linkages between Fragile X and behavioral abnormalities such as autism. Strong suggestions have been made trying to link autism and Fragile X. However experts have noted that autism does not occur more often in Fragile X than in the general population. The majority of males with the disability have autistic-like features, such as hand flappy, hand biting, rocking, and poor eye contact. There are other associations trying to draw the disability with hyperactivity and conduct disorder, but there have been no studies to prove the theory.
School performance varies. Many children, as noted above, are mildly retarded. Reading and spelling progress can be advanced in comparison to math skills. Speech disturbances can be frequent and typical. There also may be other visual-spacial abnormalities, impaired construction abilities and impaired memory.
It is difficult to speak to parents about enlarging their family if one of their children is diagnosed with Fragile X. Some experts say a family with one male child having the disorder will have one in two chances for an additional male to be affected. The family with one female child having the disorder will have one in six chances for additional females being affected.
Recent research shows that the home environment plays a significant role in improving children’s cognitive abilities. The family must show support for the child’s school program, and provide enrichment in reading, math and other academic subjects at home. Also, encouraging the child’s maturation and independence plays an important role in maximizing the abilities of the child with Fragile X. There are also parent support groups to help the parent and the family support the child.