Fragile X Syndrome

Overview

Fragile X syndrome (also called Fragile X) is the most common inherited form of mental retardation. It affects about 1 in 4000 males and 1 in 8000 females and occurs in all racial and ethnic groups.

Causes

Fragile X is caused by a genetic mutation which is inherited. Fragile X syndrome is different from Down syndrome another common genetic cause of mental retardation. Down syndrome is generally caused by an extra chromosome (the structures in cells that contain the genes) while Fragile X syndrome is caused by an abnormality in a single gene.

Symptoms of Fragile X occur because the mutated gene cannot produce enough of a protein that is needed by the body's cells especially cells in the brain to develop and function normally. The amount and usability of this protein in part determine the severity of the disorder.

Symptoms

Young children with Fragile X often but not always have delays in developmental milestones such as learning how to sit walk and talk. Symptoms may not be obvious in younger children. They may also have:

  • frequent tantrums
  • difficulty paying attention
  • anxiety
  • speech problems
  • unusual behaviors such as hand flapping and hand biting

The most noticeable and consistent effect of Fragile X is on intelligence. More than 80 percent of males with Fragile X have an IQ (intelligence quotient) of 75 or less. The effect of Fragile X on intelligence varies in females. About one-third to one-half of women with the syndrome are intellectually impaired. However among those with a normal IQ some have learning disabilities involving math attention difficulties emotional problems (such as anxiety depression and shyness) and poor social skills.

People with Fragile X syndrome also share certain medical problems as well as many common physical characteristics such as large ears a long face flat feet and overly flexible joints especially in the fingers. Some changes don't become obvious until after puberty. For example young men tend to develop enlarged testicles. In addition having Fragile X is often associated with problems with sensation emotion and behavior.

Treatment

There is no cure for Fragile X syndrome. However a variety of healthcare providers including speech/language therapists physical and occupational therapists special educators psychologists and pediatricians can all work together to help your child succeed..

Some children with Fragile X syndrome benefit from medications including antidepressants stimulants and anti-seizure drugs that improve their behavioral symptoms so that they are better able to learn.