Researchers find genes related to autism

Researchers find genes related to autism
Updated 21h 1m ago | |


Q&A FROM AUTISM STUDY

A study published in Nature answers some questions about autism's genetic roots but raises many others. USA TODAY's Liz Szabo asked experts to explain.

Q: Will the study help doctors diagnose autism?

A: Yes. Within a few years, children may be able to take a blood test to predict their risk of developing autism, says coauthor Louise Gallagher of Trinity College Dublin.

Q: Will the study help to develop new drugs for autism?

A: Doctors hope so.

The study points out new genetic targets, says co-author Anthony Monaco of the Wellcome Trust Centre for Human Genetics in the United Kingdom. Drug companies are likely to test drugs that are already "on the shelf" to see whether any existing chemicals might correct some of these newly discovered genetic flaws.

Creating hundreds of new autism drugs for each genetic problem wouldn't be practical, says study co-author Stephen Scherer. But he notes that many of these defects are clustered on the same communication pathways involved with how brain cells talk to each other. So researchers may be able to create a drug that targets an entire pathway, correcting defects along that line.

Q: Does the study explain why diagnoses of autism are 10 times more common today than a decade ago?

A: No, says Bryan King of Seattle Children's Hospital, who wasn't involved in the study. Autism now occurs in one in every 110 children, according to Autism Speaks.

Q: So why are autism diagnoses rising?

A: The trend could be related to an increase in premature birth, older parents and use of assisted reprodutive technologies, which increase the risk of autism. It's possible that increased awareness has led to more diagnoses even if the real rate hasn't changed that much, King says.




AUTISM AT A GLANCE

Autism is an umbrella name for a family of disorders that begin in childhood, last a lifetime and disrupt a person's social and communication skills.

Prevalence
• 1 in 110 U.S. children is diagnosed with autism. Boys are four times more likely than girls to have autism.
• 1 million to 1.5 million Americans have an autism spectrum disorder

Diagnosis
• Less than a decade ago, the disease was diagnosed at age 3 or 4. Now it is routinely diagnosed at 2.
• Symptoms range from mild to severe. Many people with autism display rigid routines and repetitive behaviors.

Treatment
• There is no single treatment for children with autism. Most respond best to structured behavioral programs.

Cost
• Lifetime cost of caring for a child with autism: $3.5 million to $5 million
• Annual U.S. cost: $90 billion

Source: Autism Society of America and Autism Speaks




HEALTH REPORTER TWEETS
By Liz Szabo, USA TODAY
Scientists have found dozens of new autism-related genes, according to a study that eventually could help doctors develop better ways to diagnose and treat the condition.
Yet the study, published online Wednesday in Nature, also suggests that the genetic roots of autism are quite complicated.

Unlike children with cystic fibrosis, whose disease is caused by defects in a single gene, people with autism may share little in common genetically, says study co-author Stephen Scherer, who compared the DNA of nearly 1,000 children with autism with nearly 1,300 children who don't have autism.

But even the most common genetic changes in his study were found in only 1% or less of patients, Scherer says. That suggests that "most individuals with autism are probably genetically quite unique," says Scherer of the Hospital for Sick Children in Toronto, one of 120 scientists from 11 countries working on the study, called the Autism Genome Project.

As co-author Stanley Nelson of the University of California-Los Angeles describes it: "If you had 100 kids with autism, you could have 100 different genetic causes."

Taken together, these genetic changes could explain up to 20% of cases of autism, says Hakon Hakonarson, director of Children's Hospital of Philadelphia's Center for Applied Genomics, a co-author of the study, which was funded by Autism Speaks and the National Institutes of Health.

Researchers focused on a type of genetic change called "copy number variations," places where DNA has been either inserted or deleted. Because genes include instructions for making proteins, that can lead to an overdose of a protein, an underdose, a total absence of protein or a malfunctioning one, Hakonarson says.

But much about autism remains a mystery, including the cause of the other 80% of cases, says Bryan King, an autism expert at Seattle Children's Hospital. Study authors say they need to study the genes of many more children to get more precise answers about autism's genetic roots.

But doctors may one day be able to use these findings to offer parents an early genetic test to help predict children's risk of autism, says co-author Louise Gallagher of Trinity College Dublin.

The study also could lead to new drugs, because it points out new genetic targets, says co-author Anthony Monaco of the Wellcome Trust Centre for Human Genetics in the United Kingdom.

http://www.usatoday.com/news/health/2010-06-10-autism10_st_N.htm