Genes may link autism, muscle-weakening disease

By Julie Steenhuysen

CHICAGO (Reuters) - U.S. researchers have found a genetic link between autism and a muscle-weakening disorder known as mitochondrial disease, they said on Sunday, in a finding that may open new avenues of research into the causes of autism.

"Recent studies have suggested that as many 20 percent of patients with autism have markers for mitochondrial disease," said Dr. John Shoffner, a neurologist and geneticist at Medical Neurogenetics in Atlanta, who presented his findings at the American Academy of Neurology meeting in Chicago.

"There has really not been much work done so far to push that issue," Shoffner said in a telephone interview.

Mitochondrial diseases are a set of genetic disorders in which energy-producing structures in cells are impaired. The disease is often triggered by an illness, such as a high fever, which can result in severe muscle weakening.

Shoffner wanted to see if he could identify the underlying genetic mechanisms that might explain this link.

He evaluated genetic samples and clinical information gathered on 37 children diagnosed with autism who had been evaluated at his clinic for mitochondrial disease.

They found more than 60 percent of these children had mitochondrial defects.

Shoffner said the finding needs to be confirmed in other studies, but it does help to validate the hypothesis of a link between the two conditions in a subset of patients.