Researchers find genetic link to autism

ASSOCIATED PRESS

A rare genetic variation dramatically raises the risk of developing autism, a large study showed, opening new research targets for better understanding the disorder and for treating it.

Research into the causes of autism has focused on genetic causes because so many families have multiple children with the disorder. Thus far, only about 10 percent of autism cases have a known genetic cause. Boston-area researchers estimate the gene glitch they’ve identified accounts for an additional 1 percent of cases.

They found a segment of a chromosome that has genes linked to brain development and various developmental disorders was either missing or duplicated far more often in autistic people. The defect was inherited in some cases, but was more often the result of a random genetic accident.

The results from the Autism Consortium study, released online Wednesday by the New England Journal of Medicine, confirm those of smaller studies by U.S. and Canadian research groups in the past year. The consortium verified its findings by checking two other DNA databases.

“They really did nail it,” said Dr. Andrew Zimmerman, director of the Kennedy Krieger Institute’s Center for Autism & Related Disorders in Baltimore, who was not involved in the research.

He predicted children newly diagnosed with autism or other developmental disorders now will be tested for this defect on chromosome 16 and that studies of many more DNA samples may reveal other autism-related gene variations.