RTI International - News Release - 7.9.2009

Children Often Reach Age 3 Before Being Diagnosed with Intellectual Disability

RESEARCH TRIANGLE PARK, N.C.—Despite enhanced awareness, children are often older than age 3 before they are diagnosed with fragile X syndrome, the most common inherited form of intellectual disability, according to a new study by researchers at RTI International.

The study, published online in Pediatrics, found that even with increased patient advocacy, professional recommendations regarding prompt referral for genetic testing, and increased exposure to information about fragile X syndrome, no significant changes in the age of diagnosis have occurred in the past seven years.

Fragile X is not obvious at birth and must be discovered as intellectual delays become evident. Parents in the study reported frustration with the length of time needed for diagnosis because it delays access to services and often leads to the birth of a second child with fragile X.

"Awareness of fragile X syndrome has grown as a result of research, statements by professional organizations and advocacy," said Don Bailey, Ph.D., Distinguished Fellow at RTI International and the study's lead author. "However, changing the age of diagnosis will be difficult without broader and more systemic changes in pediatric practice."

The study, composed of more than 200 families of children with fragile X syndrome, found that the average age of diagnosis of boys and girls remained relatively stable across the seven-year period, at approximately 35 to 37 months for boys and more than 41 months for girls.

The researchers found that approximately 25 percent of the families of boys and 39 percent of the families of girls had a second child with fragile x syndrome prior to the diagnosis of the first child.

"Routine genetic screening for fragile X syndrome, which would significantly benefit children and their families, would be accelerated by the development of a cheap and accurate screening test," Bailey said.

The study was funded by the Centers for Disease Control & Prevention and the Association for Prevention Teaching and Research.