Scientists Identify Autism Gene Variants That Could Lead To Treatment

By JOI PRECIPHS And REG GALE
Bloomberg News
February 19 2007

Michael Giangregorio hopes that when his sons grow up, he can tell them that the autism now affecting the younger of the two, 5-year-old Nicholas, won't be handed down to their children.

Doctors have long known autism runs in families. Now, scientists have scanned DNA from 1,168 families with multiple cases, the largest such group ever assembled, and identified gene variants that could one day spur treatments for a disorder that leaves about 1 in 150 U.S. children uncommunicative, cut off emotionally from the world.

The findings, announced Sunday, include a deleted gene, called neurexin 1, that enables communication between neurons, the nerve cells in the brain that transmit information to the body through chemical and electrical signals. The researchers also found variants in two chromosomes that have never before been linked with the spectrum of similar disorders that includes autism and Asperger's Syndrome.

"This is the most ambitious effort yet to find the locations of genes that may confer vulnerability to autism, revealing clues that will likely influence the direction of autism research for years to come," said Elias Zerhouni, director of the U.S. National Institutes of Health in Bethesda, Md.

The NIH helped sponsor the work done by 120 scientists and 50 institutions in l9 countries who began work in 2002, a group known as the Autism Genome Project Consortium. Their findings will be published in the journal Nature Genetics.

The hope is that by mapping genetic flaws tied to the disorders, scientists will be able to better understand how they work and determine whether they can be fixed, said Bernie Devlin, associate professor of psychiatry and human genetics at the University of Pittsburgh, and an author of the study.

"We'd like to think that eventually we'll be able to pinpoint individual genes that affect certain symptoms and treat them, sure" Devlin said. "That's a ways away, of course, but it's something we're working toward."

Devlin said a report earlier this month showing that manipulation of genes in mice ended symptoms of Rett Syndrome, a rare genetic disease related to autism, suggests they may be on the right track, even though the spectrum of autism disorders seen in humans offers a much tougher target.

"The finding we're announcing is just a first step," he said. "We have funding to continue working, and I'd be surprised if we don't have another big announcement within a year. While we're looking at 10,000 snips now, we will be looking at 500,000 or a million going forward." Snips are the variations in DNA that make each individual unique.

Giangregorio, who resides in Merrick, N.Y., said his son Nicholas was diagnosed with autism at about 16 months. His son Michael, who is 7, doesn't have autism, he said.

When Nicholas was first diagnosed, health officials said that about 1 in 250 children had autism. This month, the U.S. Centers for Disease Control and Prevention released new figures acknowledging the prevalence has increased to 1 in 150.