New Research Suggests Cause of Autism

PRNewswire 10may01

NEW ORLEANS -- Autism -- a poorly understood genetic disorder present in more than a half million Americans -- may be caused by a defect in metal metabolism that impairs the development of the brain and can result in hypersensitivity to toxic environmental substances. In a study of 503 autism patients, 99 percent exhibited evidence of this metabolic disorder, according to information presented here today at the annual meeting of the American Psychiatric Association. Blood and urine analyses yielded evidence of a metallothionein (MT) dysfunction in 499 of 503 patients (99 percent) diagnosed with autism spectrum disorders, according to William J. Walsh, Ph.D., biochemist and chief scientist of the Pfeiffer Center, Naperville, Ill., and Anjum Usman, M.D., a physician at the Center, who presented the findings in a presentation at the APA meeting. "MT is a family of proteins essential for many important processes in the body, and a dysfunction in this system can explain most of the classic symptoms observed in autism," said Dr. Walsh. "An MT disorder may affect the development of brain neurons and may cause impairments in the immune system and gastrointestinal tract, along with hypersensitivity to toxic metals," he said. The study included a search for distinctive chemical markers for the major components of autism spectrum conditions, including classic autism, Asperger's Disorder and pervasive development disorder with autistic features. No substantive differences were found among these populations. However all three populations exhibited a very high incidence of a severe metal-metabolism disorder. "A careful analysis indicated that all but 4 of the 503 autism-spectrum subjects exhibited evidence of a metal metabolism disorder associated with MT functioning," Dr. Walsh said. The study findings suggest that the primary cause of autism may be an inborn error in MT functioning, perhaps aggravated by an environmental insult, he said. The study findings also suggest that autism may be caused by either a genetic MT defect or a biochemical abnormality, which disables MT protein. If correct, the study finding could lead to an early infant screening test forautism predisposition, and advanced treatments to correct the metal-metabolism disorders.

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