Reviewed By Brunilda  Nazario, MD
on Wednesday, February 12, 2003
WebMD Medical News

Feb. 12, 2003 -- For the first time, a group of Duke researchers has isolated one of several genes linked with autism. It's a discovery that underscores the complexity of this disorder -- and could pave the way for better understanding of high blood pressure, diabetes, multiple sclerosis, and other complex genetic disorders.

Their report appears in the March issue of the American Journal of Human Genetics.

Autism is composed of several overlapping developmental disorders that affect social, communication, and behavioral functioning. "Many research groups have been actively looking for genetic risk factors that can lead to autism, but without much success," says researcher Margaret Pericak-Vance, PhD, director of the Duke Center for Human Genetics, in a news release.

Each autistic child has a unique set of characteristics that affect his or her behavior, communication skills, and ability to interact with others, she adds. It is the very diverse, complex nature of autism that has made it so difficult to locate distinct genetic risk factors, says Pericak-Vance.

Using what they call a "fishing net" approach, the Duke researchers sifted through data collected from families in which more than one child is affected by autism. They focused specifically on one character trait -- an "insistence on sameness" -- that is found in many autistic children.

When researchers looked at children who scored high in that trait, they discovered a strong link to the GABRB3 gene on chromosome 15q. The gene has been implicated in autism before but has never been positively linked to the disease because of the disorder's diversity. Additional research will be necessary to understand how defects in the GABRB3 gene might contribute to autistic disorder, and how other genes or environmental factors also play a role.

SOURCES: March 2003 American Journal of Human Genetics • Margaret Pericak-Vance, PhD, director of the Duke Center for Human Genetics, news release from Duke University medical Center and Healthy System, Durham, N.C.

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