Search for environmental triggers and new hopes for earlier detection

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By ph Picard | August 6, 2010 2:33 PM EDT

Trying to crack the mystery of autism

Search for environmental triggers and new hopes for earlier detection

Autism, according to the Autism Society of America, is a complex developmental

disability that typically appears during the first three years of life and

affects a person's ability to communicate and interact with others.

There is no known biological marker for autism. There is no known single cause.

There is no known cure, per se, although early intervention and treatment has

been proven to minimize the effects of the disorder.

The incidence of autism in the U.S. is increasing at an alarming rate. Twenty

years ago, about one in 5,000 children were diagnosed with autism. The current

rate, according to the U.S. Centers for Disease Control and Prevention, is 1 in

every 110.

The rate jumped 57 percent in just four years, said the CDC.

A portion of the rise in cases is attributed to a more thorough and

broad-ranging diagnostic approach. Because there is no known biological marker,

autism diagnosis is based solely on behavioral analysis.

Autism spectrum disorder, or ASD, is the umbrella term applied to those with

classic, severe autism, but also to those with milder forms of autism, including

Asperger's syndrome and pervasive developmental disorder not otherwise

specified.

But recent studies at the University of California have shown that the

increase in cases of autism cannot be solely attributed to the wide-ranging ASD

diagnosis. The disorder, that is, is actually growing in the population.

One percent of children in the U.S., ages 3 to 17, have some form of ASD.

The scientific community believes, for the most part, that autism arises

genetically. Yet scientists also say that environmental factors may contribute

to the onset of the disability by triggering predisposed genetic conditions.

" While science is still working to identify the cause of autism, exposure to

toxic chemicals in the environment is one crucial area of inquiry, " Sen. Barbara

Boxer, D-CA, said in her opening remarks to a Senate committee hearing this week

on potential environmental factors in autism.

Boxer pointed out that autism affects entire families and has financial as well

as social and emotional costs.

" The federal Interagency Autism Coordinating Committee estimates that autism

spectrum disorder's cost to society are currently between $35 to $90 billion

annually, " Boxer said.

The Autism Sociaety of America estimates the cost of autism over a life span at

$3.2 million per person.

" ASDs could result from a variety of factors, including combinations of genes,

environmental exposures and gene-environment interactions, " Anastas,

science adviser at the federal Environmental Protection Agency told the panel.

Anastas said that, judging from the latest research, " it seems prudent to assume

that at least some portion of the observed increase is real and results from

environmental factors interacting with susceptible populations. "

Since environmental exposures may be preventable, identifying possible

environmental triggers " should be a research priority, " he said.

The National Institute of Environmental Health Studies is currently conducting

research into possible environmental factors in autism. The NIEHS is looking at

the effects of air pollution from traffic, chemicals in the environment like

pesticides and flame retardants, alcohol and tobacco use by pregnant women, and

metals like lead and mercury.

There has been a controversy in recent years concerning the possible role

childhood vaccinations may play in triggering autism, due to a mercury

preservative, called thimerosol, present in the vaccines.

Several scientific studies have thrown doubt on any connection between

thimerosol and autism. In 2004, the Institute of Medicine concluded that the

" vaccine hypotheses are not currently supported by the evidence, " and that

researchers into the causes of autism should direct their studies where there is

some supporting evidence.

Diane , a speech therapist and director of autism research for the American

Speech Language Hearing Association , said the key benefit to any findings on

autism would be earlier diagnoses.

" If an environmental trigger were found, it could possibly be removed from the

child's environment, and would certainly help, " said , who was not at the

Senate hearing but spoke in a phone interview.

But since the most effective treatment for autism is early intervention, the

most welcome discovery is anything that allows an earlier detection, said.

referred to recent research in pre-verbal speech patterns that, scientists

say, can provide an early indication that a child is autistic.

The technology is called Language Environment Analysis, or LENA.

" With this method, we will be able to diagnose autistic characteristics before a

child is two years old, " said. " Early detection allows for early

intervention. Treatment can then ameliorate many of the things that cause

language and learning problems. The overcoming of these communication problems

links directly to performance in speaking, in reading, in social behavior, in

personal conduct. Anything that allows us to intervene sooner is significantly

beneficial. "

Another recent, promising discovery in autism detection comes from the United

Kingdom, where the autism rate is as high and alarming as that in the U.S.

As reported in the Journal of Proteome Research, scientists in the UK and

Australia have discovered that children with autism have a different chemical

marking in their urine than non-autistic children.

The hope is that the study could form the basis of a noninvasive test that might

help diagnose autism earlier.