News

    Scientists Discover Genetic Mutations Linked to Autism

    Christopher Astacio reads with his daughter Cristina, 2, who was recently diagnosed with a mild form of autism, New York, March 28, 2012.
    Christopher Astacio reads with his daughter Cristina, 2, who was recently diagnosed with a mild form of autism, New York, March 28, 2012.
    Jessica Berman

    Three new studies have uncovered extremely rare genetic mutations that shed new light on the potential environmental and biological roots of autism, a brain disorder that causes social and developmental delays in children, beginning at a young age.  Scientists say the DNA glitches found in a small subset of autistic children were not inherited by them, but occurred spontaneously at their conception, increasing their risk for developing the disorder.  

    One study found that having the rare genetic mutations could increase by 5 to 20 times a child's risk of developing autism spectrum disorders.  These disorders range from mild cognitive delays and developmental impairments such as Asperger's syndrome to profound social dysfunctions and repetitive behaviors.  Autism is being diagnosed, on average, in one of every 88 children in the United States, according to a recent government estimate.

    Another study turned up biological evidence to support previous observations that the mutations are four times more likely to originate in male DNA than in the female DNA, and are more likely to appear in children of middle-aged and older fathers than in those of fathers younger than 35.  Researchers speculate that the frequent turnover in a male's sperm cells increases the chance for errors in the genetic copying process.  When a parent transmits such a transcription error to his offspring, the result can be a genetic mutation in the child that can cause autism.  But researchers stress the risk of getting one of these badly-copied genes is extremely small.

    The mutations, also called "de novo" mutations, are spontaneous abnormalities that scientists say are distributed widely across the genome of affected children.  They account for a very small percentage of diagnosed cases of autism, a diverse family of disorders with a variety of suspected genetic and environmental causes.

    Mark Daly of the Center for Human Genetics at the Broad [BROH-de] Institute at Harvard University and the Massachusetts Institute of Technology, led one of the studies.  Daly says the the findings give autism researchers a starting point to better understand the biology of the disorder.

    "So it doesn't explain all of autism and, in fact, more than half of the cases of autism don't have these types of mutations," said Daly. "But because they are very rare, they allow us to pinpoint when we see multiple kids with autism with mutations in the same gene."

    Scientists say there could be hundreds of mutated autism genes that code for proteins responsible for brain development.  In the studies, all 549 children had the de novo mutations and their parents did not, allowing researchers to compare the genes of their children to that of their mothers and fathers, leading to the discovery of the DNA glitches.

    Thomas Lehner is head of genomics  at the U.S. National Institute of Mental Health, which funded one of the studies.  Lehner says the latest findings point researchers toward understanding the biological architecture of autism.

    "And even better, we can design experiments that will help us get to point where we say, 'We are now able to understand a large proportion of the genetic variants - what we call a genetic liability - to autism,'" said Lehner.

    The latest studies give researchers new drug targets for treating autism.  Mark Daly of the Broad Institute says scientists have seen promising results in animal studies.

    "It's possible to reverse some of these symptoms in mice, even after the brain is developed," he said. "So it underscores that anything we think we know, we really are not sure of, as it pertains to diseases and disorders of the brain."

    Scientists hope to identify many more autism genes within a few years.

    The three studies on the discovery of de novo genetic mutations in autism are published jointly in the journal Nature.

    This forum has been closed.
    Comments
         
    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.
    Testing Bamboo as Building Materiali
    X
    June 27, 2016 9:06 PM
    For thousands of years various species of bamboo - one of the world's most versatile plants - have been used for diverse purposes ranging from food and medicine to textiles and construction. But its use on a large scale is hampered because it's not manufactured to specific standards but grown in the ground. A University of Pittsburgh professor is on track to changing that. VOA’s George Putic reports.
    Video

    Video Testing Bamboo as Building Material

    For thousands of years various species of bamboo - one of the world's most versatile plants - have been used for diverse purposes ranging from food and medicine to textiles and construction. But its use on a large scale is hampered because it's not manufactured to specific standards but grown in the ground. A University of Pittsburgh professor is on track to changing that. VOA’s George Putic reports.
    Video

    Video Orphanage in Iraqi City Houses Kids Who Lost their Parents to Attacks by IS

    An orphanage in Iraqi Kurdistan has become home to scores of Yazidi children who lost their parents after Islamic State militants took over Sinjar in Iraq’s Nineveh Province in 2014. Iraqi Kurdish forces backed by the U.S. airstrikes have since recaptured Sinjar but the need for the care provided by the orphanage continues. VOA’s Kawa Omar filed this report narrated by Rob Raffaele.
    Video

    Video Re-Opening Old Wounds in a Bullet-Riddled Cultural Landmark

    A cultural landmark before Lebanon’s civil war transformed it into a nest of snipers, Beirut’s ‘Yellow House’ is once again set to play a crucial role in the city.  Built in a neo-Ottoman style in the 1920s, in September it is set to be re-opened as a ‘memory museum’ - its bullet-riddled walls and bunkered positions overlooking the city’s notorious ‘Green Line’ maintained for posterity. John Owens reports from Beirut.
    Video

    Video Brexit Resounds in US Presidential Contest

    Britain’s decision to leave the European Union is resounding in America’s presidential race. As VOA’s Michael Bowman reports, Republican presumptive nominee Donald Trump sees Britain’s move as an affirmation of his campaign’s core messages, while Democrat Hillary Clinton sees the episode as further evidence that Trump is unfit to be president.
    Video

    Video New York Pride March A Celebration of Life, Mourning of Loss

    At this year’s march in New York marking the end of pride week, a record-breaking crowd of LGBT activists and allies marched down Manhattan's Fifth Avenue, in what will be long remembered as a powerful display of solidarity and remembrance for the 49 victims killed two weeks ago in an Orlando gay nightclub.
    Video

    Video NASA Juno Spacecraft, Nearing Jupiter, to Shed Light on Gas Giant

    After a five-year journey, the spacecraft Juno is nearing its destination, the giant planet Jupiter, where it will enter orbit and start sending data back July 4th. As Mike O'Sullivan reports from Pasadena, California, the craft will pierce the veil of Jupiter's dense cloud cover to reveal its mysteries.
    Video

    Video Orlando Shooting Changes Debate on Gun Control

    It’s been nearly two weeks since the largest mass shooting ever in the United States. Despite public calls for tighter gun control laws, Congress is at an impasse. Democratic lawmakers resorted to a 1960s civil rights tactic to portray their frustration. VOA’s Carolyn Presutti explains how the Orlando, Florida shooting is changing the debate.
    Video

    Video Tunisian Fishing Town Searches for Jobs, Local Development Solutions

    As the European Union tries to come to grips with its migrant crisis, some newcomers are leaving voluntarily. But those returning to their home countries face an uncertain future.  Five years after Tunisia's revolution, the tiny North African country is struggling with unrest, soaring unemployment and plummeting growth. From the southern Tunisian fishing town of Zarzis, Lisa Bryant takes a look for VOA at a search for local solutions.
    Video

    Video 'American Troops' in Russia Despite Tensions

    Historic battle re-enactment is a niche hobby with a fair number of adherents in Russia where past military victories are played-up by the Kremlin as a show of national strength. But, one group of World War II re-enactors in Moscow has the rare distinction of choosing to play western ally troops. VOA's Daniel Schearf explains.
    Video

    Video Muslim American Mayor Calls for Tolerance

    Syrian-born Mohamed Khairullah describes himself as "an American mayor who happens to be Muslim." As the three-term mayor of Prospect Park, New Jersey, he believes his town of 6,000 is an example of how ethnicity and religious beliefs should not determine a community's leadership. Ramon Taylor has this report from Prospect Park.
    Video

    Video Internal Rifts Over Syria Policy Could Be Headache for Next US President

    With the Obama administration showing little outward enthusiasm for adopting a more robust Syria policy, there is a strong likelihood that the internal discontent expressed by State Department employees will roll over to the next administration. VOA State Department correspondent Pam Dockins reports.
    Video

    Video Senegal to Park Colorful ‘Cars Rapides’ Permanently

    Brightly painted cars rapide are a hallmark of Dakar, offering residents a cheap way to get around the capital city since 1976. But the privately owned minibuses are scheduled to be parked for good in late 2018, as Ricci Shryock reports for VOA.

    Special Report

    Adrift The Invisible African Diaspora