Siblings of Autistic Children at a Higher Risk for the Disorder; Can That Risk Be Lowered?

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More research finds a family-based risk of autism among siblings, which raises the question of what parents can do to lower the risk among potentially at-risk youngsters.

Researchers from Aarhus University in Denmark report in the journal JAMA Pediatrics that children with an older brother or sister diagnosed with an autism spectrum disorder (ASD) are more likely to be on the spectrum themselves.

According to their study of about 1.5 million children born in Denmark between 1980 and 2004, those who had an older sibling diagnosed with autism had close to a seven-fold increased risk of developing autism as well. Siblings who shared the same mother and father had a 7.5 greater risk of having autism, whereas maternal half siblings had a 2.4 greater risk. Paternal half siblings didn’t have a statistically significant increase in risk.

(MORE: Induced and Augmented Labor Linked to a Higher Autism Risk)

The results clearly support the strong role that genetics plays in autism. And the higher rates among half siblings who share a mother also highlight the role that pregnancy factors could play. Last week, researchers from Duke University and the University of Michigan reported that augmented or induced labor, for example, could contribute to a higher risk of autism among children.

For parents, the findings raise difficult questions about how proactive they should be in screening for the disease among their younger children if older siblings are affected. Alycia Halladay, senior director, environmental and clinical sciences for Autism Speaks, says parents who have already had a child diagnosed on the spectrum should alert their doctor to the family history. During check-ups, when a doctor asks about inherited disorders like cystic fibrosis, they now typically include autism on the check-list.

Mothers of autistic children can also take steps during pregnancy to lower the risk of autism in their next offspring, such as taking prenatal folic acid and avoiding overexposure to toxins. That attention could even extend to the infants’ first few years, since studies suggest that some intensive behavior therapies can help to mitigate the symptoms of autism. “We know that early intervention can make a real lifetime of difference. So be very vigilant during that child’s life, all the way from birth to the well baby check-ups, six months, 12 months, and 18 months,” says Halladay. “Make sure you are watching for the signs and symptoms of autism. Consult your pediatrician, and if you do notice the signs and symptoms of autism you can receive help free of charge from a state-based early intervention agency.”

Researchers are also developing tests that can detect the genetic risk factors associated with the disorder, and more of these biomarkers may become available as additional gene-based contributors emerge. Scientists from University of Utah and the Children’s Hospital of Philadelphia, for example, recently identified 24 new gene variants associated with autism spectrum disorders in January.

(MORE: Using Movement to Diagnose and Treat Autism)

Understanding what these various gene differences mean, however, is still a work in progress. “The genetic tests that are out there really look for specific genes that we know are associated [with ASDs], but if you don’t have these specific genes, there could be a combination of other genes your child has that could increase that risk,” she says. “Just because your child doesn’t have that biomarker, doesn’t mean that child is not at risk. There is a lot we don’t know about genetics, that we still need to understand to get to a point where we are comfortable saying here is definite risk marker, or here is a test that a parent can take.”

For now, simply being aware that siblings of autistic children may be at higher risk of the disorder could help parents to pay more attention to the signs and symptoms of autism so they can alert their doctors as early as possible in the child’s development.

23 comments
OnTheCrown
OnTheCrown

My son has autism.  His three younger siblings do not.  We didn't vaccinate them.  They should compare the rates of autism between younger sibs who were vaccinated and those who weren't.

mathari
mathari

Psycho-socialists claimed, for the last 100 years, that complex disorders afflicting us were caused by our genes.This became the cornerstone explanation while we dumped insane amounts of toxins into our environment.Meanwhile, the rate of complex disorders such as autism, schizophrenia, and cancer, have increased exponentially as we poisoned our environment with toxins such as lead and mercury.  We dumped so much mercury into our waterways that eating more than one serving of fish a week is hazardous to our health. 

The real scientists always knew that mapping the genome would expose this “missing heritability” which is now estimated, according to GWAS, to be a variance of +/-1%. Those eugenists were motivated by prejudice or profit.Most were hired or funded by Dupont, GM, and oil companies.

We are now pouring millions of tons of antifreeze into our water supply. In ten years, we will see an explosion of cancer rates and violent diseases, the likes of which have never been seen. It will be a problem of epidemic proportions.  The methane escaping from these wells alone will heat the planet ten times faster than carbon.We did this all to ourselves.

AlainCouvier
AlainCouvier

It's exciting to see new research that once again underlines the important issue that Autism as a developmental disorder is driven primarily by environment rather than genes.

It is also exciting to confirm that there are varying 'windows of vulnerability' that essentially program an infant in the womb towards a diagnosis that may include not only Autism , but anxiety , depression , bipolar disorder and schizophrenia.

Of course it is not only the prenatal environment that does so, it also applies to another 'window of vulnerability' the post natal environment. Particularly as we now understand that significant physiology, neurology and genetics explode in a burst of activity just prior to and after birth.

Tied into all of this ecology is the immune system and the chronic inflammatory state that is evidenced in an ASD child's physiology, neurology and genetics. Further exploration of this mix of environment and immune system dysfunction could lead to remarkable treatment of core Autism behaviors.

Those days are very close with clinical trials beginning via a number of researchers in a variety of eminent ASD medical centers.

It is essential to see not only the 'big picture' of Autism as a medical condition with a developmental timeline from conception to adulthood. But to also realize that at the heart is a patient with all the essential vulnerability that brings.


ps Congratulations to those researchers, that continue to move ASD understandings and knowledge forward.


California Institute of Technology - Patterson Lab - Maternal Immune Activation (Influenza) and continuing insights into ASD immunology

University of California Davis - MIND Institute - Maternal antibodies 23% of ASD children

University of California Los Angeles - Center for Autism Research and Treatment - Immune and Neurogenesis genetic hubs / pathways

Boston Children's Hospital - Autism and Epilepsy

Harvard Medical School - Co-Morbid conditions in Autism




cycle3man
cycle3man

Hey Alexandra Sifferlin: If genetics are involved with this ground swell of newborns being struck Autistic. I ask, "Where are all the 40, 50 60 year old AUTISTICS????? Do they not have the same GENES????

cycle3man
cycle3man

Quote From The Article: "More research finds a family-based risk of autism among siblings, which raises the question of what parents can do to lower the risk among potentially at-risk youngsters."


Cycle3man  Comment: Bull!

MaurineMeleck
MaurineMeleck

There is no such thing as a genetic  epidemic.  Genetic   research is a waste of time and money.  We are still waiting for that fully vaccinated vs fully unvaccinated study of children. Why has

n't the gov't done it?

All these recent genetic studies, and concentrating on such reasons as fat mothers, old fathers, odd lungs, weird placentas, highway fumes, too much rain etc. are simply ways to draw our attention from the vaccines.

Thanks to Ms Dachel for her honest and inspiring work. Much more truthful and compelling than the majority of journalists today.

Maurine Meleck, SC

grandmother to 1 in 31(vaccine injured)

 Autism is medical!

nrdavis
nrdavis

AnneDachel has yet again posted the material that she reflexively posts in response to virtually any article that mentions autism, and yet again she has made the same logical errors.

Indeed, as Dachel notes, more and more scientific articles indicate that the intrauterine environment strongly influences the risk that the developing fetus will go on to develop autism. Factors such as maternal infection during pregnancy, maternal diabetes, intake of prenatal vitamins, maternal obesity, etc. can markedly increase the risk that the baby will develop ASD. Every day more and more evidence supports the importance of prenatal influences on the risk of developing ASD. A study published yesterday in JAMA Pediatrics again shows that while the younger siblings of children with ASD are at much greater risk than the general population for developing ASD, maternal half-siblings are at greater risk than paternal half-siblings--thus, both genetics and the prenatal environment are important risk factors. Dachel doesn't like this, because, as someone who trained to teach history to adolescents, she knows more than any scientist about the causes of ASD, and she is absolutely certain that the conclusions she reached years ago cannot be contravened by evidence.

Dachel yet again posted that "Nothing explains why a healthy, thriving baby suddenly and dramatically loses learned skills (many stop talking completely), and regresses into autism following routine vaccinations."

That's an odd statement, since Dachel must certainly know that children who regress into autism have been shown to have followed an abnormal brain growth pattern that developed long before parents could possibly note any regression.Dr. David Amaral said at the 2011 International Meeting for Autism Research that his work: "confirmed . . . that there is this precocious brain growth [in autism] . . . but in our cohort, which is about 200 children that we analyzed, [an aberrant pattern of brain growth] is most prominently associated with children that have a regressive form of autism; these are the kids that seem to highlight the vaccine issue, because these children have normal development to 12 to 18 months and then lose social ability and lose language function and regress back into autism . . . so it actually casts doubt on the idea that a vaccine . . . would be actually the precipitating factor, because [the abnormal brain growth patterns] were starting much, much earlier than that." [Nordahl CW, et al. Brain enlargement is associated with regression in preschool-age boys with autism spectrum disorders. Proc Natl Acad Sci U S A. 2011 Dec 13;108(50):20195-200.]

AnneDachel1
AnneDachel1

It seems that every week there's at least one new study announcing yet another association/link to autism. There are now dozens of things being talked about: older moms, older dads, moms who drink, or smoke, or who take anti-depressants while pregnant, and moms who live too close to freeways. Autism is linked to babies born too large or too small and to moms who have siblings too close together.

Nothing is ever conclusive. Nothing is causal. Nothing explains why a healthy, thriving baby suddenly and dramatically loses learned skills (many stop talking completely), and regresses into autism following routine vaccinations. If researchers really wanted to conduct worthwhile research they'd do a simple comparison study looking at fully-vaccinated and never vaccinated kids. If one in every 50 never vaccinated children also has autism, the hottest controversy in pediatric medicine would be ended. It would be clear that THERE IS NO LINK.

No official will call for such a study, despite the fact that retrospective studies like this are common. There are now so many parents too scared to vaccinate that the study group is out there.

Unless and until this study is done, the question remains open.

Anne Dachel, Media editor: Age of Autism

AnneDachel1
AnneDachel1

"Mothers of autistic children can also take steps... to lower the risk of autism" by "avoiding overexposure to toxins." Would that include NOT getting a mercury-laced flu vaccine during pregnancy? Most of the vaccine available contains the mercury-based preservative, thimerosal. This vaccine is recommended for pregnant women at all stages of pregnancy. The flu shot has 25 mcg of mercury and according to the EPA, that much mercury can be safely processed by someone weighing 550 pounds.

And it's not true that thimerosal is "safe mercury." There's no such thing.

Thimerosal was invented in 1930 by the drug company Eli Lilly. They tested it on 22 patients dying of meningitis. All the subjects were dead by the end of the "study" but Eli Lilly said it was safe. That was the only test done on thimerosal. After the creation of the FDA, its use was just continued.  In the last few years, there have been a number of easily flawed and manipulated population studies on mercury-containing vaccines which show no link to autism, but each of them has been found to have ties to the pharmaceutical industry. 

Anne Dachel, Media editor: Age of Autism

drnance
drnance

While I agree that there does appear to be a certain genetic weakness among individuals affected by autism, addressing the trigger, toxic exposure, should be key to decreasing the risk in additional siblings.  If autism were merely a genetic disorder, this doesn't explain the alarming increase in autism rates when compared to the rather stagnant birth rate.  Prolonged toxic exposure by the mother, fetus, and child is the key to this disorder.  The argument could also be made that while there may be a genetic component, siblings, in particular, grow up in the same household, with the same parents, who have the same attitudes toward health, disease, and toxic exposure.  You can't ignore that siblings, above and beyond genetics, will have nearly identical environmental risk factors unless there is some drastic change in the lifestyle or behaviors of that family from one child to the next.  Additionally, chiropractic spinal adjusting should be included early on to decrease nervous system interference and maximize nervous system function, especially in those families with a history of autism.   I'll refer you to my blog post - http://healthpotential.wordpress.com/2013/08/16/the-autism-conundrum/ 

AlainCouvier
AlainCouvier

Important points from the authors.


* The recurrence rate was only 6.1% (that's very important for parents to understand)

* The recurrence rate was much lower than previous studies eg 14.2% , 18.7%

* The recurrence rate in younger siblings ranged from 4.5% to 10%

* The elevated risk was only 6.9 x

* An influenza viral infection in pregnancy has a 2x risk (Schizophrenia over 7x)

* The pattern of prevalence in Denmark where this study was undertaken is substantially different from the United States and other Western countries. Suggesting other factors including environment are at play with greater impact.


nrdavis
nrdavis

 Maurine Meleck wrote, yet again, that “All these recent genetic studies, and concentrating on such reasons as fat mothers, old fathers, odd lungs, weird placentas, highway fumes, too much rain etc. are simply ways to draw our attention from the vaccines.”

Well, I suppose that that just might make sense if (1) you are unable to understand (despite clear evidence) that continued replication during the production of sperm routinely increases the mutation burden; (2) you refuse to accept (despite clear evidence) that children with respiratory problems and ASD were uniformly shown to have abnormal lung development that dated to early in gestation; (3) you can’t accept that placental defects (which clearly develop long before exposure to postnatal vaccination) were associated with the risk of ASD; (4) you aren’t willing to acknowledge (despite the evidence) that environmental factors during gestation affect the risk that the fetus will develop ASD, AND you believe that (4) the scientists and clinicians who don’t accept what you have gleaned from nonsensical anti-vaccine websites are all in thrall to their reptilian overlords.

OTOH, people who actually have studied these subjects disagree with you.

nrdavis
nrdavis

@MaurineMeleckwrote, yet again, that "There is no such thing as a genetic  epidemic."

I wonder if you understand that the evidence very clearly shows that most, if not all, of the apparent increase in the prevalence of ASD is due to a handful of non-genetic factors including diagnostic substitution, diagnostic accretion, changes in diagnostic practices, and increased awareness of ASD among both parents and health care providers

 

VitoAlexanderPavlovic
VitoAlexanderPavlovic

@nrdavis so if Anne Dachel is wrong, why are the drug companies and their defenders so afraid to do a vaccinated versus non-vac study? it would end the controversy at once.

nrdavis
nrdavis

Dachel has yet again confused the safety of daily (life-long) exposure with intermittent and rare exposure, but she could solve her problem by consulting any introductory toxicology text.

Dachel also seems to be ignorant of the evidence that links infection during pregnancy with the risk that the developing fetus will eventually become schizophrenic or autistic.

nrdavis
nrdavis

@AnneDachel1wrote: " They tested it on 22 patients dying of meningitis. All the subjects were dead by the end of the "study" but Eli Lilly said it was safe."

 The patients were expected to die. They died. What is your point?

VitoAlexanderPavlovic
VitoAlexanderPavlovic

@drnance drnance, thanks for your superb comment, perhaps some of these people  will begin to realize that there is a trigger and that trigger for some just may be the vaccines, and those children that account for the real increase in autism rates.

AndrewKilroy
AndrewKilroy

@AlainCouvierSo essentially they have proven that attempts to predict risk about Autistics are bunk.


This whole article is cretinous. I resent being called a risk, like I am some living, human cancer. 

For those ready to brand me 'high-functioning' I remember being non-verbal and despite the lies Autistics have the almost universal capacity for speech. No wonder when they're treated like trash and misunderstood that they don't learn to.

VitoAlexanderPavlovic
VitoAlexanderPavlovic

@nrdavis @AnneDachel1 her point is that the study was done on patients that died from meningitis, so then how does this prove  thimerisol safety? it doesn't, and you couldn't figure this out? no wonder you're still defending dangerous toxins like vaccines, you're clueless that's why!