Lack of amino acid linked to autism

Some children may have an inherited weakness predisposing them to develop autism when exposed to mercury from fish or other sources, an American environmental group says.

New research shows that some children may lack sufficient levels of glutathione, an amino acid involved in several cell processes, including the metabolism of toxins, says the Environment Working Group.

"When compared with normal, healthy children, autistic children showed a significant impairment in every one of five measurements of the body's ability to maintain a healthy glutathione defence," the group's report says.

"Reduced antioxidant defence may characterise a group of individuals who are demonstrably more sensitive to the effects of a range of toxic chemical exposures, and shed light on increasing rates of related learning and behavioural disorders."

The group says the findings by former Food and Drug Administration senior research scientist Dr Jill James, now of the University of Arkansas for Medical Sciences, reopen the debate on whether vaccines containing a mercury-based preservative called thimerosal may cause autism, for which there is no known cure.

- REUTERS