Stanford scientists describe autism discoveries

By Lisa M. Krieger

STANFORD - Nobody knows what causes autism, and scientists have all but given up on finding one gene, chemical or brain structure that explains it.

But there are new clues about the biological complexities underlying this behavioral disorder, which affects one in 88 children, according to a weekend conference sponsored by Stanford University's Autism Center.

Researchers at the conference told families about recent findings in brain chemistry, size, connections, and genetics that shed light on the disorder. Ultimately, such work will improve diagnosis and treatment.

"If all this research just changes just one life, it's worth it," said Kevin Iudiello, of Burlingame, whose son Parker, 12, was diagnosed when he was 18 months old.

"It can truly be amazing to have another person with you in life who thinks, sees and hears things like no one else in the world. It forces you to look at everything in life uniquely," said Iudiello, an entrepreneur and investment banker. "But I'm also acutely aware of the challenges of navigating autism."

Although autism is rooted in biology, the most effective interventions so far are behavioral and educational; medicine plays a lesser role in its management.

Researchers at the conference described emerging evidence about:

Brain chemistry. A mounting body of evidence shows that the brain chemicals oxytocin and vasopressin, which promote trust and bonding, play a role in the disorder -- and could someday be used to help diagnose and treat patients, according to Karen Parker and Dean Carson of Stanford University School of Medicine.

After experimental treatment with oxytocin, patients showed increased recognition and understanding of other people's emotions, Parker reported. Oxytocin also improved brain function during social situations and decreased brain function -- reducing obsessive over-attentiveness -- in non-social situations.

Stanford scientists are also studying potential treatment with a related chemical, called vasopressin. In non-autistic men, a single dose of vasopressin can boost social function, increase the ability to remember a happy or angry face and improve memory for positive and negative words, said Carson. His team hopes to learn if it helps autistic people, as well.

Brain size. Improved neuroimaging techniques reveal distinct features in the autistic brain, according to Stanford School of Medicine's Antonio Hardan.

He found enlargement in the cerebral volume -- specifically, size and thickness of the gray matter -- in the brains of children with autism. The precise significant of this "overgrowth" is not yet known, and size seems to decline with age, he said.

In contrast, he found that another part of the brain, called the corpus collosum, is smaller in children with autism. And it remains small during adulthood. This is the structure that connects the two hemispheres of the brain. He will continue to study what this finding means to the lives of patients.

Brain connectivity. Scientists no longer believe that a certain part of the human brain governs a specific function.

Instead, "basically everything we do is dependent on interconnected activity between multiple brain systems," involving 100 billion neurons, said Lucina Uddin of the University of Miami. "They are all connected in an intricate way," with connections strengthening as we age.

Differences have been found in the connectivity of brains in people with autism, suggesting that alterations in important neural pathways and networks contribute to the disorder, she said.

"Are there too many (connections)? Not enough? Or some combination of over and under? That is where it gets controversial," she said. "We have to get more nuanced in our understanding of the disorder. We have to figure out how they go wrong."

Genetics. There are likely several different partial causes and combinations of genes that contribute to autism, said Dr. Joachim Hallmayer and his team at Stanford's School of Medicine.

Genetics is thought to play a role in about 30 to 40 percent of cases, according to the California Autism Twin Study. It is associated with many genetic syndromes, such as "Fragile X."

Tests can identify a genetic culprit in about 10 to 15 percent of cases of autism when there is an associated intellectual disability, he said. Genetic testing is most useful in cases where there are other medical problems or a family history.

But genetic testing is less useful if a person is healthy, has no intellectual disability and no family history, he added.

Families applauded the scientific progress.

"You have to learn what is best for your kid," said Iudiello, "and that means digging in and learning the research."

Stanford Autism Center

The Stanford Autism Center at Lucile Packard Children's Hospital is dedicated to diagnosing, treating and advancing research on autism spectrum disorders. For more information, go towww.stanfordchildrens.org/en/service/autism or call 650-723-7704.

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