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Dr. Stephen Scherer at Sick Kids Hospital in Toronto has done research which shows that the roots of autism are in the genome.

The last of three articles I have reproduced here article states that:

Some advocacy groups believe an environmental factor, such as mercury, must be damaging the genes to cause autism.

"For example, if you expose cells to radiation, you can produce similar types of effects," Lieberman, who was not involved in the study, said in a telephone interview.

"But these types of copy number variations do not (necessarily) implicate an environmental agent."

There would seem to be no need for chelation therapy in light of today's science.

The articles:

http://bodyandhealth.canada.com/channel ... etails.asp?
news_id=11740&news_channel_id=41&channel_id=41&rot=11

Canadian-led research identifies new genetic regions linked to autism

Provided by: Canadian Press

Written by: SHERYL UBELACKER
Feb. 18, 2007


TORONTO (CP) - In the genetic equivalent of looking for a needle in a haystack, a Canadian-led international research team has pinpointed a new region of DNA thought to cause at least some cases of autism in children.

Researchers at Toronto's Hospital for Sick Children and the Offord Centre for Child Studies in Hamilton teamed with scientists and clinicians from centres elsewhere in Canada and eight other countries to scan the entire human genome for autism-related genes.

The consortium of scientists - 137 from 50 centres worldwide that make up the Autism Genome Project - analyzed DNA from about 1,600 families with autistic children to try to zero in on a specific group of brain cells and the genes that affect their development and function.

Their analysis led them in part to a region on chromosome 11, as well as to a gene known as neurexin 1, part of a family of genes believed to be important in communication between neurons, particularly during the brain's development.

The findings, part of the largest genome scan ever conducted in autism research, were published online Sunday in the journal Nature Genetics.

Children with autism have difficulty interacting and communicating with others - including family members. They often exhibit repetitive behaviours such as rocking back and forth, flapping their hands or hitting themselves. The complex disorder affects about one in 165 children, making it the most common form of childhood neurological disorder or developmental disability.

"We first used genome-scanning technology to test genetic markers in autistic children and find regions in the genome linking to autism susceptibility genes," said study co-author Dr. Stephen Scherer, a senior scientist in genetics at Sick Kids.

Scherer was the co-discoverer with an American scientist of common genetic variants in the worldwide general population. What they found, in essence, is that a person's DNA does not contain just two sets of genes, one from each parent, but also on occasion multiple copies of one or more genes and some that are missing altogether.

They dubbed these extra or missing parts of the genome "copy number
variations," or CNVs.

It was CNVs that the scientists working on the Autism Genome Project were looking for in their DNA scans of individuals affected by autism.

"What we found was a little bit surprising," Scherer said in an interview, noting that previous, smaller studies by other researchers had zeroed in on different parts of the genome, including regions on chromosomes 2, 7 and 17.

"We didn't find any of those regions," he said of the genetic analysis, which alone took about a year of scientific slogging to complete. "We did not find (anything in) those regions, but we found a region on chromosome 11, which was quite exciting."

What's important about the discovery, said Scherer, is that it has given scientists in the field a new foundation for further research, which eventually could lead them to specific mutations on specific genes that cause - likely in combination - the spectrum of disorders that fall under the autism umbrella.

"We have a good understanding of what the architecture of the genome looks like in autistic individuals now," he said. "We didn't have that before."

Co-author Dr. Peter Szatmari, director of the Offord Centre for Child
Studies, said the discovery has huge implications for autistic patients and their families in the future.

"Not only have we found which haystack the needle is in, we now know where in the haystack that needle is located," said Szatmari, who is also head of child psychiatry at McMaster University. (The human genome is made up of about 30,000 genes, each containing 100,000 "letters," or chemical base-pairs called nucleotides.)

"This is a major breakthrough in our efforts to better understand the disorder and improve diagnosis and treatment for patients and their families," he said.

Scherer said the study shows that certain classes of genes likely contribute to the development of autism, "so we have a better understanding of what we need to do to correct it. It's enlightened us on what the causes are."

"We still don't have a definite answer, but we're one step along the way."

Dr. Robert Hegele, a professor of medicine and biochemistry at the University of Western Ontario who was not involved in the study, said the research suggests there are many different forms of genetic susceptibility in autism.

Isolating those areas could one day allow for a test that would confirm the autism diagnosis in children exhibiting symptoms and tell family members whether they, too, carry the combination of genetic defects that could be passed on to their children.

"So maybe you'd be testing for 30 or 40 different genetic susceptibilities at the same time as opposed to a single gene," Hegele, who holds the Canada Research Chair in Human Genetics at UWO, said from London, Ont.

"It's a major step, it's a significant increment in knowledge and understanding of the architecture of these traits at the genetic level," he said of the study.

"The implications would go beyond autism to other complex diseases that are common and have a similar impact, like heart disease and diabetes, and so on."

http://www.labcanada.com/issues/ISArtic ... e=02192007

Toronto, ON - Fresh from their latest discovery and supported by $26.7 million in public and private funding, Canadian and international scientists have launched the second phase of a global scientific effort to map the genes responsible for causing autism.

The first phase of the multi-million dollar Autism Genome Project achieved its goal of assembling the largest biobank in the world and conducting the most comprehensive genome scan in autism genetics, aimed at finding susceptibility genes. This research was performed by 137 scientists from more than 50 institutions representing 8
countries who formed a first-of-its-kind autism genetics consortium, the Autism Genome Project (AGP). Results from phase 1 were published this week in the distinguished scientific journal Nature Genetics.

Building on this success, the coalition of researchers, including a Canadian team led by Dr Stephen Scherer of the Hospital for Sick Children and Dr Peter Szatmari of the Offord Centre for Child Studies, will now apply gene-chip technologies to scan the genome for association with new genetic markers, as well as sub-microscopic copy
number variations (CNVs) along chromosomes in autism.

These findings will guide high-throughput DNA sequencing experiments designed to pinpoint underlying changes in DNA sequences in autism susceptibility genes. The unprecedented statistical power generated by the AGP will ultimately allow researchers to confirm the role of these genes in autism spectrum disorders.

"In essence, we will be looking at the genes to see if there is any abnormality that might cause this complex developmental disorder," says Dr Szatmari. "We also want to know if the genes interact to create a combined effect that is more powerful than each alone, or whether they operate only in certain subgroups of children, such as females, those who are higher functioning, or those who have Asperger Syndrome."

"The availability of the Centre for Applied Genomics, a provincially and nationally supported genomics infrastructure, will allow us to scan the genomes at the highest resolution, for both samples from Canada and around the world, making the Canadian contribution central to the AGP's success," says Dr Scherer.

A total of $26.7 million over the next three years is being provided by public and private partners, including Genome Canada/Ontario Genomics Institute and the Canadian Institutes of Health Research. Other funding partners include Autism Speaks, the British Medical Research Council (MRC), the Health Research Board of Ireland (HRB), Southwest Autism Research and Resource Center (SARRC), the Hilibrand Foundation, the McLaughlin Centre for Molecular Medicine, IBM, the
Catherine and Maxwell Meighen Foundation, and SickKids Foundation. This combination of international, public and private partners funding a consortium of clinicians and scientists is a first in the field of autism research.

"The Autism Genome Project is an important example of Canadian researchers working with their colleagues around the world to address an important challenge in human health. This research will yield a better understanding of autism, lead to earlier diagnosis, and more effective interventions for children and their families affected by autism," says Dr Alan Bernstein, president of the Canadian Institutes
of Health Research (CIHR).

http://abcnews.go.com/Technology/wireStory?id=2954418

DNA "glitches" tied to autism, researchers say

By Maggie Fox, Health and Science Editor
Reuters

Mar 15, 2007 — WASHINGTON (Reuters) - Little glitches in the DNA of people with autism suggest that the disease might be caused by as many as 100 different genes, researchers reported on Thursday.

The study is one of several new reports on autism in recent months, which have shown the disease is far more common and more complex than many experts had believed.

"These findings certainly complicate the search for genes contributing to autism. These are rare changes, dispersed across the genome, and they tell us that autism may be the final common path for many different genetic abnormalities," said Dr. Thomas Insel, director of the National Institute for Mental Health, which helped
fund the study.

The small changes are not what people usually think of as genetic mutations but are called copy number variations — extra copies or missing stretches of DNA.

For instance, one child with Asperger syndrome was missing DNA from a
stretch of 27 genes.

The findings suggest that autism spectrum disorder may involve 100 or more genes, the researchers report in Friday's issue of the journal Science.

Experts know autism has a genetic cause, and in February the U.S. Centers for Disease Control and Prevention reported it affects about one in every 150 children.

For the study, Dr. Jonathan Sebat of the Cold Spring Harbor Laboratory in New York and colleagues across the United States, in Finland and in Britain looked at the DNA of people in 264 families.

"We performed whole-genome scans on all parents, patients and unaffected children," the researchers wrote. New technology to sequence genes rapidly, as well as several published sequences of the human genome, have helped scientists do this in recent years.

NOT A FAMILY AFFAIR

Usually, tests of DNA of people with diseases show that everyone in a family who has the disorder carries the same mutation or pattern of mutations.

But that's not the case here. The researchers found numerous spontaneous mutations in 14 of 195 people with autism spectrum disorders compared to two of 196 unaffected people.

And of the 14 autism patients with mutations, only two had relatives with autism.

"Our results show conclusively that these tiny glitches are frequent in autism, occurring in at least 10 percent of cases, and primarily in the sporadic form of the disease, which accounts for 90 percent of affected individuals," Sebat said in a statement.

Dr. Jeffrey Lieberman, chairman of the department of psychiatry at Columbia University Medical Center in New York, said such work does not answer one overwhelming question about autism — what causes these genetic changes in the first place.

Some advocacy groups believe an environmental factor, such as mercury, must be damaging the genes to cause autism.

"For example, if you expose cells to radiation, you can produce similar types of effects," Lieberman, who was not involved in the study, said in a telephone interview.

"But these types of copy number variations do not (necessarily) implicate an environmental agent."

Autism is marked by a variety of difficulties in social interaction and behavior, and range from the awkwardness of Asperger syndrome to severely debilitating repetitive behaviors and an inability to speak.

The recent studies suggest that these important abilities are scattered throughout the human genome, and that small changes anywhere can have broad effects, Lieberman said.

"This is just one piece of information that is going to add to the evolving story but more is needed," he said.