Messages that must be sent and received for proper brain development and functioning are disrupted when this protein is missing. When the gene is altered, it can cause developmental delays and mild to severe learning disabilities including mental retardation.

Most children with fragile X appear completely typical at birth, but gradually, developmental characteristics of the condition become evident.

"My daughter isn't sitting up on her own, and her younger cousin is."

"He's still not talking at 18 months."

"My child cries all the time. I feel so frustrated, I don't know what to do."

"My son had recurrent ear infections. I had no idea that they are common in fragile X children."

The FMR1 gene was discovered in 1991. Fragile X is passed on by a carrier - a person  who may show no signs of impairment, but whose gene changes as it is passed on to a child.

When a father passes on FMR1 it remains relatively stable, but he will pass on this gene to all of his daughters and none of his sons. With each succeeding generation the expanded area can become less stable and increases the likelihood that one's child may be fully affected by fragile X. The gene expands to the affected range only when passing from mother to child. This is why fragile X can travel silently through generations, undetected, and then appear.

When a carrier mother passes on the FMR1 gene there is a 50 percent chance that each child will inherit the mutated gene. The size of the expansion does not correlate to the degree of affectedness.

Even today, many people with fragile X are not correctly diagnosed. Worldwide, it is estimated that one in every 2,000 boys and 1 in every 4,000 girls is affected.

One in 260 women and one in 700 men carry the fragile X gene.

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Children may have some or none of the common physical or behavioral fragile X features. The variability of symptoms contributes to the difficulty of diagnosing it.

Most boys have several physical characteristics and impairments and tend be more severely affected than girls. Because girls have two X chromosomes, the unaffected chromosome may compensate for the altered fragile X gene and girls tend to exhibit milder and fewer characteristics.
Learning disabilities can be slight or severe and range from math or reading difficulties to mental retardation.

Anyone with undiagnosed mental retardation in his or her family should be tested.  A simple DNA blood test is now available to determine if a child is affected by the condition or if a person carries the fragile X gene. The same test can be used for prenatal diagnosis.

Diagnosis is essential to early intervention programs involving occupational, physical, speech and sensory integration therapies. Individualized intervention plans, including medications if indicated, can greatly improve a child's ability to reach his or her full potential.

Many medications are also available which can help with behavior issues. Currently, only the symptoms of fragile X can be treated. Research on treating the "root cause(s)" of the condition is moving forward at an increasing pace.

Not yet. But recent progress has been made. With continued funding for research there is great hope for future generations.

"I got very excited when we first discovered the fragile X gene," said Dr. James D. Watson, Nobel Laureate and co-discoverer of the structure of DNA. "I think it was the first triumph of the Human Genome Project. With fragile X we've got just one protein missing, so it's a simple problem. So, you know, if I were going to work on something with the thought that I were going to solve it, oh boy, I'd work on fragile X."