News / Health

Researchers Discover New Autism Genes

A large international team of scientists has discovered rare genetic changes that predispose some people to autism. The complex neurological disorder affects about one percent of children. It impairs their ability to communicate and develop social relationships and, in many cases, causes behavioral difficulties.

The study identifies a number of genetic mutations, called copy-number variants, in the genomes of children diagnosed with autism.   

Copy-number variants are segments of DNA that have been duplicated or deleted in the genes of children with autism.  Investigators say some of the genetic abnormalities appear to be inherited while others are unique to the autistic children.

In the study, researchers from eleven countries compared the genomes of nearly 1,000 autistic children to 1,300 children without the condition, searching for the rare variants, some of which had been previously implicated in connection with autism. They found these mutations occur 20 percent more often in children with the neurological disorder.

Andy Shih, with the organization Autism Speaks, likens the latest discoveries to pieces of a jigsaw puzzle: "With these findings you are starting to find some of the edge pieces. So, that would provide you with some sort of a framework for looking at how these genes work in autism and leading to the clinical features and how it might work in collaboration with the environment that can lead to some of the autism that we see around us," he said.

Investigators say the copy-number variants in the autistic children disrupt normal functioning in a number of areas, including pathways associated with synapses, the structure between brain cells that allows chemicals to pass electrical and chemical signals to other neurons.

They also found genetic mutations involved in the reproduction and signaling of cells.

Stanley Nelson is a professor of human genetics at the University of California in Los Angeles and co-author of the study.  

He says while the mutations make individuals more susceptible to autism, the genetic abnormalities do not automatically mean someone will have the disorder. "It's probably not a hundred percent and we just haven't observed it enough yet.  So one of the challenges now is to observe these types of mutations across larger sample sets such that you could determine what is the real risk if you inherit this sort of variant or what's the risk if you have a mutation that your parents didn't have," he said.

Autism is what is known as a spectrum disorder, meaning that people could be only mildly affected, a condition known as Asperger's syndrome, while others with autism are profoundly disabled.

Nelson says his team did not find an association between the number of genetic insertions and deletions and the severity of autism.

To pinpoint the causes of the disorder, Nelson says scientists need to conduct a much larger study decoding the genes that have been implicated in this research. "Each child who's affected has some genetic information in their genome that we would like to learn from. And that's the quickest route to try and dissolve [solve] the riddle that is autism," he said.

An article describing genetic changes in children diagnosed with autism is published this week in the journal Nature.

You May Like

Video Getting to Zero AIDS Infections

More than 35 million people around the world are infected with HIV, a disease that is both preventable and treatable

Children, Childhoods Lost in European Refugee Crisis

According to UNICEF, 190,000 children applied for political asylum in Europe in the first 9 months of this year - twice as many as last year

What Happened When I Landed in Antarctica

Refael Klein chronicles what it's like to visit one of the coldest, most desolate places on Earth

This forum has been closed.
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
With HIV, Can We Get to Zero?i
Carol Pearson
November 29, 2015 1:23 PM
The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video With HIV, Can We Get to Zero?

The theme of this year's World AIDS Day is "Getting to Zero." The U.N. says new HIV infections have been reduced by 35 percent since 2000 and AIDS-related deaths are down by 42 percent since the peak in 2004. VOA's Carol Pearson takes a look at what it might take to actually have an AIDS-free generation.

Video Political Motives Seen Behind Cancelled Cambodian Water Festival

For the fourth time in the five years since more than 350 people were killed in a stampede at Cambodia’s annual water festival, authorities canceled the event this year. Officials blamed environmental reasons as the cause, but many see it as fallout from rising political tensions with a fresh wave of ruling party intimidation against the opposition. David Boyle and Kimlong Meng report from Phnom Penh.

Video African Circus Gives At-Risk Youth a 2nd Chance

Ethiopia hosted the first African Circus Arts Festival this past weekend with performers from seven different African countries. Most of the performers are youngsters coming form challenging backgrounds who say the circus gave them a second chance.

Video US Lawmakers Brace for End-of-Year Battles

U.S. lawmakers are returning to Washington for Congress’ final working weeks of the year. And, as VOA's Michael Bowman reports, a full slate of legislative business awaits them, from keeping the federal government open to resolving a battle with the White House over the admittance of Syrian refugees.

Video Taiwan Looks for Role in South China Sea Dispute

The Taiwanese government is one of several that claims territory in the hotly contested South China Sea, but Taipei has long been sidelined in the dispute, overshadowed by China. Now, as the Philippines challenges Beijing’s claims in an international court at The Hague, Taipei is looking to publicly assert its claims. VOA’s Bill Ide has more from Beijing.

Video After Terrorist Attacks, Support for Refugees Fades

The terrorists who killed and injured almost 500 people around Paris this month are mostly French or Belgian nationals. But at least two apparently took advantage of Europe’s migrant crisis to sneak into the region. The discovery has hardened views about legitimate refugees, including those fleeing the same extremist violence that hit the French capital. Lisa Bryant has this report for VOA from the Paris suburb of Cergy-Pontoise

Video Syrian Refugees in US Express Concern for Those Left Behind

Syrian immigrants in the United States are concerned about the negative tide of public opinion and the politicians who want to block a U.S. plan to accept 10,000 Syrian refugees. Zlatica Hoke reports many Americans are fighting to dispel suspicions linking refugees to terrorists.

Video Thais Send Security Concerns Down the River

As Thailand takes in the annual Loy Krathong festival, many ponder the country’s future and security. Steve Sandford reports from Chiang Mai.

Video Islamic State Unfazed by Losses in Iraq, Syria

Progress in the U.S.-led effort to beat Islamic State on its home turf in Iraq and Syria has led some to speculate the terror group may be growing desperate. But counterterror officials say that is not the case, and warn the recent spate of terror attacks is merely part of the group’s evolution. VOA National Security correspondent Jeff Seldin has more.

Video Belgium-Germany Border Remains Porous, Even As Manhunt For Paris Attacker Continues

One of the suspected gunmen in the Nov. 13 Paris attacks, Salah Abdeslam, evaded law enforcement, made his way to Belgium, and is now believed to have fled to Germany. VOA correspondent Ayesha Tanzeem makes the journey across the border from Belgium into Germany to see how porous the borders really are.

Video US, Cambodian Navies Pair Up in Gulf of Thailand

The U.S. Navy has deployed one of its newest and most advanced ships to Cambodia to conduct joint training drills in the Gulf of Thailand. Riding hull-to-hull with Cambodian ships, the seamen of the USS Fort Worth are executing joint-training drills that will help build relations in Southeast Asia. David Boyle reports for VOA from Preah Sihanouk province.

Video Uncertain Future for Syrian Refugee Resettlement in Illinois

For the trickle of Syrian refugees finding new homes in the Midwest city of Chicago, the call to end resettlement in many U.S. states is adding another dimension to their long journey fleeing war. Organizations working to help them integrate say the backlash since the Paris attacks is both harming and helping their efforts to provide refugees sanctuary. VOA's Kane Farabaugh reports.

VOA Blogs