Autism linked to increased oxidative stress

[Guest guest]

Autism linked to increased oxidative stress

Apr 3, 2005, 10:33

Dr. and colleagues measured plasma levels of the major

intracellular antioxidant glutathione and its metabolic precursors in 95

autistic children and 75 children without autism. Glutathione levels (and

also the ratio of reduced to oxidized glutathione or redox ratio) were

significantly decreased in the autistic children, indicating presence of

a significant level of oxidative stress.

By Federation of American Societies for Experimental Biology , Chronic

biochemical imbalance is often a primary factor in the development of

many complex diseases but a possible metabolic basis for autism has not

been well explored. Now Arkansas Children's Hospital Research Institute

researchers report for the first time that children with autism have a

severely abnormal metabolic profile indicating increased vulnerability to

oxidative stress. The scientists also identified a significant increase

in the frequency of several genetic polymorphisms that they believe may

increase the risk of autism in specific combinations yet to be

determined.

Autism is a neurodevelopment disorder characterized by impairment in

social interactions, limited language acquisition, repetitive behaviors,

and restricted interests. Usually diagnosed before the age of three, the

disorder appears to have increased tenfold over the last 15 years, now

affecting more than 30 of every 10,000 children in the United States.

Although both genetic and environmental factors are believed to

contribute to the development of autism, no firm causal evidence exists.

And with no available physiological or biochemical markers, diagnosis

currently is made entirely on a behavioral basis.

Dr. and colleagues measured plasma levels of the major

intracellular antioxidant glutathione and its metabolic precursors in 95

autistic children and 75 children without autism. Glutathione levels (and

also the ratio of reduced to oxidized glutathione or redox ratio) were

significantly decreased in the autistic children, indicating presence of

a significant level of oxidative stress. Oxidative stress occurs when the

antioxidant system fails to counteract the generation or exposure to free

radicals. Unopposed free radicals can damage sensitive cells in the

brain, the gastrointestinal tract, and the immune system, and the

researchers believe they may contribute to the neurological,

gastrointestinal and immunologic pathology that occurs in autistic

children.

Working with a larger number of autistic (360) and non-autistic controls

(205), the researchers then looked at common polymorphisms in genes that

could directly or indirectly affect these metabolic pathways and induce

oxidative stress. Three (the catecho-O-methyltransferase gene, the

transcobalamin II gene, and the glutathione-S-transferase M1 gene) were

found to be significantly elevated in the autistic children. These genes

are prevalent in the general population, says Dr. , and clearly do

not " cause " autism. However, she and her colleagues believe

specific combinations of these and additional genetic changes could

promote the chronic metabolic imbalance seen in the children and thus

increase the risk of the disorder.

The next step, says Dr. , is to determine whether the metabolic

profile discovered by the researchers could be used as a diagnostic test

for autism to support the purely behavioral diagnosis currently in use.

It also would be important, she says, to determine whether the abnormal

profile is present in high-risk children, such as toddler siblings of

autistic children and/or toddlers with developmental delays.

http://www.rxpgnews.com/psychiatry/learning-disabilities/autism/article_931.shtml

[Guest guest]

This is a good example of that bad research the people believe in.

Dr. ' measurements on cysteine don't agree with anyone else's,

raising grave questions as to the reliability of any of her OTHER

measurements.

Andy

> Autism linked to increased oxidative stress

> Apr 3, 2005, 10:33

>

> Dr. and colleagues measured plasma levels of the major

intracellular

> antioxidant glutathione and its metabolic precursors in 95 autistic

> children and 75 children without autism. Glutathione levels (and

also the

> ratio of reduced to oxidized glutathione or redox ratio) were

significantly

> decreased in the autistic children, indicating presence of a

significant

> level of oxidative stress.

>

> By Federation of American Societies for Experimental Biology , Chronic

> biochemical imbalance is often a primary factor in the development

of many

> complex diseases but a possible metabolic basis for autism has not been

> well explored. Now Arkansas Children's Hospital Research Institute

> researchers report for the first time that children with autism have a

> severely abnormal metabolic profile indicating increased

vulnerability to

> oxidative stress. The scientists also identified a significant

increase in

> the frequency of several genetic polymorphisms that they believe may

> increase the risk of autism in specific combinations yet to be

determined.

>

> Autism is a neurodevelopment disorder characterized by impairment in

social

> interactions, limited language acquisition, repetitive behaviors, and

> restricted interests. Usually diagnosed before the age of three, the

> disorder appears to have increased tenfold over the last 15 years, now

> affecting more than 30 of every 10,000 children in the United States.

> Although both genetic and environmental factors are believed to

contribute

> to the development of autism, no firm causal evidence exists. And

with no

> available physiological or biochemical markers, diagnosis currently

is made

> entirely on a behavioral basis.

>

> Dr. and colleagues measured plasma levels of the major

intracellular

> antioxidant glutathione and its metabolic precursors in 95 autistic

> children and 75 children without autism. Glutathione levels (and

also the

> ratio of reduced to oxidized glutathione or redox ratio) were

significantly

> decreased in the autistic children, indicating presence of a

significant

> level of oxidative stress. Oxidative stress occurs when the antioxidant

> system fails to counteract the generation or exposure to free radicals.

> Unopposed free radicals can damage sensitive cells in the brain, the

> gastrointestinal tract, and the immune system, and the researchers

believe

> they may contribute to the neurological, gastrointestinal and

immunologic

> pathology that occurs in autistic children.

>

> Working with a larger number of autistic (360) and non-autistic

controls

> (205), the researchers then looked at common polymorphisms in genes

that

> could directly or indirectly affect these metabolic pathways and induce

> oxidative stress. Three (the catecho-O-methyltransferase gene, the

> transcobalamin II gene, and the glutathione-S-transferase M1 gene) were

> found to be significantly elevated in the autistic children. These

genes

> are prevalent in the general population, says Dr. , and clearly

do not

> " cause " autism. However, she and her colleagues believe specific

> combinations of these and additional genetic changes could promote the

> chronic metabolic imbalance seen in the children and thus increase

the risk

> of the disorder.

>

> The next step, says Dr. , is to determine whether the metabolic

> profile discovered by the researchers could be used as a diagnostic

test

> for autism to support the purely behavioral diagnosis currently in

use. It

> also would be important, she says, to determine whether the abnormal

> profile is present in high-risk children, such as toddler siblings of

> autistic children and/or toddlers with developmental delays.

>

>

http://www.rxpgnews.com/psychiatry/learning-disabilities/autism/article_931.shtm\

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