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Genetic research reveals pieces of autism puzzle
April 5th, 2012
02:02 PM ET

Genetic research reveals pieces of autism puzzle

As the number of children with autism has increased over the past couple of decades, so have efforts to find causes behind this neurodevelopmental disorder. Research published Wednesday provides new clues about genetic glitches that may contribute to the development of autism among children.

Ten years ago, little was known about the role genetics plays in autism. But improved technology has allowed scientists to delve deeply into DNA to search for answers.

"Ten years ago [it was like] we were looking through binoculars, then we were looking at autism through a microscope, and now it's like looking at it in high definition," says Andy Shih, vice president of scientific affairs for the advocacy group Autism Speaks, who was not involved in the research.

Since the first human genome was sequenced in the early 2000s, researchers have had the opportunity to search for genes that cause the disorder, which affects an estimated 1 in 88 children in the United States.

Researchers were originally searching for a single gene that would cause the disorder, but they now believe it's much more likely that there are multiple genetic mutations that put a child at risk. By studying specific areas of the DNA of families that have a child with autism, scientists have identified approximately 1,000 genes that may be involved.

A person's whole genome consists of about 3 billion nucleotides, or “letters,” of DNA. But only 1.5% of it - a portion called the "exome" - produces proteins. The exome also harbors 85% of disease-causing mutations, according to the National Institutes of Health.

Three studies published in the journal Nature this week analyzed the exomes of parents and children with autism and found spontaneous genetic mutations in the exome play a significant role in raising a child's risk of developing autism.

One study looked at 238 families with one child with autism and one child without autism.

Life with autism: In their own words

"We found ... several sequence changes [mutations] in the base pairs of DNA that are not seen in a parent," says study co-author Dr. Daniel Geschwind, professor of neurology and psychiatry at UCLA School of Medicine. "These mutations are not inherited, but either occur in the mother's egg or father's sperm (before conception) or in the child itself (after conception)."

Geschwind says this new research suggests a child with these mutations "has a much higher chance" of developing a disorder like autism. This research team, led by Dr. Matthew State of Yale University, found at least 14% of those with autism had multiple genetic mutations, which is five times the normal rate, according to the NIH.

Another research team headed by Evan Eichler, a professor of genome studies at the University of Washington, found 39% of spontaneous mutations were likely to increase the risk of autism because they interfere with biological developments that are important for communication in the brain.

Eichler's research also  found these spontaneous mutations were "overwhelmingly paternal in origin," suggesting the origin of these mutations are in a father's sperm.  This supports previous research that suggested there's an increased risk of a child developing autism if the father is older.

The third study in Nature, led by Mark Daly, associate professor at Harvard Medical School, found many mutations seen in children with autism are not necessarily connected to the disorder. His research found that the mutations that are linked to autism are spread over many genes, and so may not be enough to cause the disorder.

In addition to these three studies, an independent study published in Science Translational Medicine, found a non-protein-producing gene can also contribute to the risk of autism.

"All four of these studies get us closer to understanding the biology of autism," says Daniel Campbell, lead author of the fourth study, and assistant professor of psychiatry and the behavioral sciences at the University of Southern California.

Looking at this research collectively further supports the notion that autism is a neurodevelopmental disorder, and that the disruptions in development that lead to autism are laid down very early in brain formation, says Dr. Bryan King, director of the Seattle Children's Autism Center.

"This [research] is yet another example of how we don't have any single gene that can be connected in a straight line to autism," says King, who wasn't involved in the research.

"There's no one gene that causes autism," says James Sutcliffe, one of Daly's co-authors and an associate professor of molecular physiology, biophysics and psychiatry at Vanderbilt University. "But what these studies do show is that several genetic mutations increase the risk of getting autism and different mutations may affect people in a different way."

Much more research is needed, but ultimately identifying more genetic mutations could pinpoint targets for researchers to focus on to find ways to counteract the developmental disabilities they can cause. Or maybe, in the future, this research could lead to diagnostic tests that could identify children who are at risk for autism so they can get the earliest possible interventions.


soundoff (135 Responses)
  1. JLS639

    This appears to be from a press release. I cannot find the articles in the April 5th or March 29th issues.

    April 5, 2012 at 18:49 | Report abuse | Reply
    • Pastor Mike Palevo

      The next time that want your kids Vaccinated, ask for all the ingredients first. See what they tell you! Big Pharm and Doctors are money hungry criminals.

      April 5, 2012 at 22:37 | Report abuse |
    • CWST

      @Pastor Mike Palevo You really are a conspiracy nut aren't you? In that case, you might as well also claim that the pharmaceuticals paid off the entire scientific community for the rest of their lives in a massive global conspiracy against us too. You do realize that means these highly respected researchers at Yale, Harvard, USC, UCLA, UW, Vanderbilt, and more worldwide have been all paid off to make these claims. I'm sure they would feel insulted. Not to mention the reputable scientific and medical journals. But no, I'm sure disgraced and questionable individuals from the past two decades are more reliable sources. You do realize how much money they would need to pay off all these people and keep them quiet for the rest of their lives, while also requiring them to risk their licenses and reputations right?

      April 5, 2012 at 23:03 | Report abuse |
    • Soulcatcher

      @CWST – you are more of an anti-conspiracy nut than Pastor Mike is a conspiracy nut so let's stop throwing out those arguments and get to the facts and people's experience on these matters.

      I've worked as an accountant in these scientific communities. Fact: There is a defininate paper trail of money going to these academics and researchers from corporations. Who funds these research grants? How are they funded?

      It's pathetic what scientists make on paper (hint payroll records), but I'm surprised to see all BMWs, Audis, Lexus, Mercedes in the lab parking lot for just 1 supervisor making $80K.

      April 9, 2012 at 07:47 | Report abuse |
    • Jhon Doe

      Let me see,,,uhm???? the people that claims that vaccines are the cause, and the pharm companies are responsable use Drugs from the same pharm companies to cure their sons.

      November 12, 2013 at 12:40 | Report abuse |
  2. donnas

    I'm sure a genetic component allows for certain people to survive most disease states, however, the logarithmic dumping of articificial chemicals / pesticides in our food, soil, air and water over the past few decades has caused more autism / ADHD than any genetic predisposition for these states. (I never knew anyone in the 1950's with these health issues.) The phthalates in plastics with their estrogen-like composition also are doing a lot to change the very character of our children. Where is the outrage? Where are all the lawsuits? Can you imagine the chaos and drastic changes in our mass-consumptive society when the real truth comes out about these poisons...and what will be required of us to sustain a clean environment for future generations. Massive change on the way!

    April 5, 2012 at 19:04 | Report abuse | Reply
    • CWST

      Those would still be genetic mutations, because prolonged contact with various chemicals can cause genetic mutations.

      April 5, 2012 at 21:50 | Report abuse |
    • dx2718

      In the 1950's, children with special needs may have been more hidden and/or ignored, so there may have been many cases that you just didn't know about.

      April 6, 2012 at 00:37 | Report abuse |
  3. donnas

    I'm sure a genetic component allows for certain people to survive most disease states, however, the logarithmic dumping of articificial chemicals / pesticides in our food, soil, air and water over the past few decades has caused more autism / ADHD than any genetic predisposition for these states. (I never knew anyone in the 1950's with these health issues.) The phthalates in plastics with their estrogen-like composition also are doing a lot to change the very character of our children. Where is the outrage? Where are all the lawsuits? Can you imagine the chaos and drastic changes in our mass-consumptive society when the real truth comes out about these poisons...and what will be required of us to sustain a clean environment for future generations. Massive change on the way!
    CNN: I have not stated this comment before. It's amazing how you are scrutinizing my comments--making it unable for me to post.them.....

    April 5, 2012 at 19:07 | Report abuse | Reply
  4. Mom of a Autistic Child

    I vaccinated ALL of my children – so that's 3 boys and 2 girls. Only my first born is Autistic.

    April 5, 2012 at 19:32 | Report abuse | Reply
  5. Boltsy

    I am willing to bet there is a direct correlation between the sharp increase in autism and the proliferation of cellphones, cell towers and wifi.

    Of course, you will never hear mainstream anything admit that...

    April 5, 2012 at 22:54 | Report abuse | Reply
    • dx2718

      There is surely a correlation between anything that has increased over the last few decades and anything else that has increased over the last few decades. That doesn't mean there is any relationship between the two. Here's an example: texting has increased over the last few years. So has the popularity of Justin Bieber. But that doesn't mean that Beiber is popular because of texting, or that texting is popular because of Bieber.

      April 6, 2012 at 00:39 | Report abuse |
    • SixDegrees

      There's a very strong correlation between shoe size and reading ability. There's no causation involved, however; just because kids feet get bigger as they get older doesn't impact their continuously improving reading talents, nor vice versa. Correlation is meaningless in isolation. Without some actual mechanism connecting the correlated data, it's just more noise, and refuge for idiocy.

      April 6, 2012 at 07:00 | Report abuse |
  6. maurinemeleck

    Government health officials, doctors and the media have failed our children. They have no idea what causes autism or how to cure it. So instead they proclaim these genetic studies as the holy bible. They pour tens of millions of dollars into a pot of genes, throw in some spin and then cover-up the real autism epidemic. What's inside the pot is something nobody in their right mind can stomach. Amazing how this study comes on the heels of the new numbers from the CDC, which axctually aren't even new numbers(from 2008) There is no such thing as a genetic epidemic.Even a fifth grader knows that.
    And boy how the media has spread this study around like like deadly pesticides on our fruits and veggies. The autism community doesn't fall for tblatant act of dishonesty and cover-up.
    Maurine Meleck SC
    grandmother to 2 vaccine injured boys-one recovered with bio-med treatments.

    April 5, 2012 at 23:22 | Report abuse | Reply
  7. 2 Data Points

    I have 2 children. The first one was fully vaccinated and has autism,
    the second one was not vaccinated and is neuro-typical.

    I am sure there are many cases like this.

    I dont think autism is caused entirely by vaccines but some Drs or books say ... the environment loads the gun and vaccines pull the trigger.
    Genes play a role in the individual's ability to detoxify and deal with viruses.

    I'd like to see statistics on vaccinnated and un-vaccinated children. The rate of autism in the unvaccinated children must be a lot lower than the vaccinated ones. THis may not prove anything in a sceintific way but at least poeple would know that vaccinating at the recommended schedule highly increases the chances of ASD.

    Also, the goverment has an agency that compensates families affected by vaccines and poeple have been compensated.

    April 6, 2012 at 02:24 | Report abuse | Reply
    • 1

      The data's been out there for years. Just go to Google Scholar and look up the articles. It's fairly definitive for any study that has a p<0.05 for data relating vaccines to autism.

      Children who get vaccines are overwhelmingly more likely to be diagnosed with autism than children that don't get vaccines.
      Compare that to children who are never vaccinated, and the evidence is undeniable.

      Of course, the data shows definitively that children who don't get vaccinated have an overwhelming increase in likelihood for death and permanent neurological disability due to meningitis infection instead of getting an autism diagnosis, but like nearly all people who don't vaccinate their children, we'll just ignore that little tidbit of information.

      April 6, 2012 at 05:08 | Report abuse |
    • Bob

      People who vaccinate are more diligent in taking children to doctors when something is wrong with the child – more cases of autism would thus be found among children who are vaccinated despite the fact that it makes no difference.

      April 6, 2012 at 09:50 | Report abuse |
  8. look around retards

    AUTISIM IS CUASED BY PINK SLIME! Our population is growing at an alarming rate even though women are waiting longer now to have kids it doesn't stop indias growth or china's growth if you want to figure whats going on on the outside start with what you put in the inside PINK SLIME PESTICIDES FLOURIDE IN THE WATER! COMEON THIS IS ALL EFFECTING US!

    April 6, 2012 at 05:09 | Report abuse | Reply
  9. aymie

    i think the genetically modified foods have something to do with this

    April 6, 2012 at 06:32 | Report abuse | Reply
  10. Bob

    Autism is all due to Ronald Reagan. Ever since he was elected everything has been falling apart.

    April 6, 2012 at 09:51 | Report abuse | Reply
    • Bob

      This was just to preempt all those who are bound to blame it all on Obama.

      April 6, 2012 at 09:52 | Report abuse |
    • Soulcatcher

      Actually it's the Republicans because they are against all Americans getting a college education. They want most of us dumb, autistic and undeducated. Look at Santorum's comments about Obama being elitist because he said Americans should strive to get a college education.

      April 9, 2012 at 07:56 | Report abuse |
  11. Dennis Jennings

    many interesting similarities to fetal alcohol syndrom, Sugar consumption, (sucrose and fructone) seem ro rise in paralell with the rise in autism. a meta data search on diet and pesticides may be revealing.

    April 7, 2012 at 01:05 | Report abuse | Reply
  12. Kent in Dallas TX

    @DavidMD, O How Lovely, Jaremie, Pastor Mike & others,

    I believe what the physicians & medical researchers say.

    I don't pay attension to what uninformed people like Jenny McCarthy say.

    Because I have a BS in Math, an MS in Math & over 20 years of experience as a programmer, I tend to believe scientific evidence from recognized experts.

    Physicians & medical researchers have their own children vaccinated.

    If there were any reasional doubt about the safety of vaccines, doctors wouldn't have their own kids vacccinated or advise everyone else to get own kids vaccinated.

    No vaccine is perfectly 100% safe or effective; however it is incredibly dangerous to refuse vacinations.

    When we eventually have an epidemic of childhood disease, a lot of beau@DavidMD, O How Lovely, Jaremie, Pastor Mike & others,

    I believe what the physicians & medical researchers say.

    I don't pay attension to what uninformed people like Jenny McCarthy say.

    Because I have a BS in Math, an MS in Math & over 20 years of experience as a programmer, I tend to believe scientific evidence from recognized experts.

    Physicians & medical researchers have their own children vaccinated.

    If there were any reasional doubt about the safety of vaccines, doctors wouldn't have their own kids vacccinated or advise everyone else to getiful kids whom their parents refused to vaccinate will die horrible deaths.

    April 7, 2012 at 11:12 | Report abuse | Reply
    • Soulcatcher

      I know three Drs. that don't have their kids vaccinated.

      April 9, 2012 at 07:58 | Report abuse |
    • I call BS

      And I know 10 who do. Anecdotes do not equal statistics.

      April 9, 2012 at 12:29 | Report abuse |
  13. Kent in Dallas TX

    My message got mangled somehow.

    Please read the comments after "beat"
    starting with the 2nd at sign ("@").

    I appoligize for any confusion or trouble that I caused.

    April 7, 2012 at 11:21 | Report abuse | Reply
  14. christiem8

    http://www.mendelsaccountant.info

    April 9, 2012 at 09:11 | Report abuse | Reply
  15. YouTube Ron Paul 2012!

    Uncover the HIDDEN LYME DISEASE EPIDEMIC! It is the most political and corrupt disease of our time! Hundreds of thousands are suffering and dying, including children, while the world turns their back and does NOTHING!
    http://lymedisease.org/news/tag/lyme-disease-and-autism
    http://www.lymebook.com/lyme-autism-connection
    http://www.underourskin.com/
    Under the Eightball Trailer 2 YouTube

    April 20, 2012 at 12:26 | Report abuse | Reply
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