A Blood Test for Autism?

Earlier detection of autism, relying on markers in the blood, may help more children to take advantage of helpful behavioral therapies.

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Earlier detection of autism, relying on markers in the blood, may help more children to take advantage of helpful behavioral therapies.

Diagnosing autism currently requires hours of observation by clinicians and a far from objective series of behavioral measures, but improvements in genetic testing could make the process more efficient.

In a study published in the journal PLOS ONE, researchers from Boston Children’s Hospital  describe a new experimental test to detect the developmental disorder, based on the differences in gene expression between kids with autism spectrum disorder (ASD) and those without the condition. The blood-based test appears to predict autism relatively accurately, at least among boys, and has already been licensed to a company, SynapDx, for commercial development. In an email statement to TIME, a spokeswoman for SynapDx said the company plans to start clinical trials of the new test in early 2013.

(MORE: Autism Studies Confirm Genetic Complexity and Risk for Older Fathers)

The new blood test for autism is intriguing, researchers say, because it seems to be at least as effective as any other genetic test for autism that doctors currently use. Scientists believe that autism has some genetic basis, based on genes that have been associated with the disorder, and the fact that the condition seems to run in families. “A week does not go by where you don’t hear about a genetic mutation that has been linked to autism in at least a few families,” says Isaac Kohane, a pediatric endocrinologist and computer scientist at Children’s Hospital Boston, and the senior study author on the new article in PLOS ONE. Kohane is a scientific adviser for SynapDx, but says he does not own any stock in the company.

But autism is a complex condition, he says, with many possible genetic determinants. And the precise genetic mechanism, or more likely mechanisms, are still poorly understood. But to get a better idea of which genetic changes might be most relevant to the disease, Kohane and his colleagues compared 66 patients with ASDs and 33 similar patients who were not affected by the disorder. Because they couldn’t analyze the participants’ brain tissue, they relied on their blood as a proxy for revealing any differences. And indeed, they found certain markers in the blood of autistic participants that did not appear in those without the disorder. They traced these to 489 genes and narrowed that list down to 55 genes that could predict autism in about two-thirds of those with the disease.

(MORE: Studies: New Clues to the Genetic Roots of Autism)

“There are a lot of different mutations involved, and a lot of different pathways that seem to be involved in autism,” Kohane says. Those genetic pathways included some known to be related to learning, and some linked to immune function. “The fact that not all kids had both, and some kids would be more abnormal in immunological pathways and others would be more abnormal in [another pathway] spoke, I think, to the genuine heterogeneity of the disease,” Kohane says.

“In that respect, autism is beginning to look a lot like what the cancer biologists are telling us about breast cancer, or lung cancer,” he says. “There may be hundreds of different molecularly defined cancers, which each have their own specific optimal treatment.” Similarly, autism spectrum disorders, too, may have diverse genetic roots, and appear clinically in slightly different ways from one patient to another.

(MORE: Gene Expression in the Brain Offers Clues to Autism’s Roots)

Today, 1 in 88 kids suffers from an autism spectrum disorder, and prevalence has soared over the last 30 years, although it’s not clear why. Diagnosing the disease early is important because it allows children to take advantage of behavioral intervention programs that can lead to higher IQ scores and improvements in language. Kohane says the blood test could identify those at risk of autism well before symptoms appear around age 2, and help these children access potentially beneficial therapies.

The test, however, is still in early stages of development. Kohane says that its accuracy (at around 70% in a high-prevalence, predominantly male sample) is high enough to be clinically useful among kids with a suspected developmental disorder. But he stresses that the test as it stands still generates too many false positives, or people mistakenly identified with the condition when in fact they don’t have it, for the test to be used as an autism screening tool among all children. If the current results are confirmed, that may take a few more years.

6 comments
kezzae
kezzae

This is a very interesting story that shows a possible way to help children with special needs. Take the time to read this article. 

ASDParent
ASDParent

@ Maurine - it may not be hard to diagnosis some forms of Autism but for "higher-functioning autism" the diagnosis can be costly and time consuming. My son has what will eventually be considered "High-functioning autism" but is currently Asperger's syndrome. As a mother I knew something was "not right" and suspected Autism. I got a referral for Autism screening from our Pediatrician at Kaiser Permanente's Autism center in Sacramento, CA and after a 1/2 a day we were told "he's just really really smart and shy " but not Autistic. Time went on, I doubted their assessment and as his preK teachers expressed similar concerns (without me every bringing them up), my husband and I decided to have him screened by another Autism center who instead of conducting a 1 time in office screening that took 1/2 a day including paperwork. This center spent over 12 hours observing my child in a variety of settings, reviewed video tapes, interviewed teachers, and used all of the accepted screening tools available and low and behold - he wasn't just "shy and smart". That cost us over $1200 then we had to fight with our insurance company for his services. As obvious to me that a child who is extremely bright but won't/can't make eye contact, is majorly obsessed with maps, and cannot play with other children no matter how long he has to warm up to them (in this case M-F 8 - 4 all year at preschool) is on the spectrum it apparently was not cut and dry to the first autism center.  I also had to push for the referral in the first place because two pediatricians who knew my son felt he would "grow out of it" (no he didn't, he just grew more and more obvious). So for children "higher" on the spectrum a test like this could expedite getting services. I still fight daily for my son which is ridiculous (in that I have to) and exhausting. The thing that makes it difficult is that he is excellent at talking to adults and they find him charming (he is but I'm biased ;) so when you ask about Autism screening they think you have lost your marbles. I can tell you as a mother of a child with Aspergers and a woman with both bachelors and masters degrees in education, I can usually recognize an Asperger's child and I have seen several who have been "screened" by school psychologists and dismissed. We have a child at a our bus stop who is 12 and obsessed with Thomas the Train, who speaks in a flat monotone voice and can't make eye contact with anyone but his mother and has no friends but the school psych who did the training said, "Good news - he's not on the spectrum" which may be "good news" but the reality is he probably is on the spectrum and as a result of the crappy diagnosis by an untrained person he very likely isn't getting all of the help he needs and also isn't qualifying for the medical benefits he would with an Autism dx.  A blood test might help children like this get a quicker and more accurate dx from the start. I suspect this boy will eventually be diagnosed as his problems continue to magnify but in the mean time he's not getting the help he should.

MaurineMeleck
MaurineMeleck

First, diagnosis is not hard because it's difficult to miss a child with autism. Secondly, there is no such thing as a genetic epidemic so how early will they draw this blood? Lastly, my grandchildren were not born with autism and neither were tens of thousands  of other children who were developing normally until they regressed following a series of vaccinations.

Maurine Meleck, SC

bepatienz
bepatienz

@MaurineMeleck  Early intervention may be helpful to children with ASD. The senior author of this report indicates that the blood test could identify those at risk of autism well before symptoms appear around age 2 and help these children access potentially beneficial therapies. The median age of diagnosis reported in the most recent report (March 2012) from CDC's Autism and Developmental Disabilities Monitoring Network revealed that many--most--children with ASD were diagnosed rather late to experience potentially advantageous early intervention, with the median reported age diagnos of 48 months for Autistic Disorder, 53 months for ASD/PDD, and 75 months for Asperger Disorder. [MMWR Surveill Summ. 2012 Mar 30;61(3):1-19.]

The timing of the blood draw is immaterial, since the characteristic ASD-related genetic changes that can be detected by this test date from the time of conception, and are thus, of course, detectable long before the first behavioral symptoms of ASD are manifest.

Finally, your grandchildren were not born walking, but that behavior developed according to a pre-determined genetically-programmed sequence of develeopment which produced the observed behavior about the time that the children received various vaccines. You might be interested in the robust scientific literature that shows that children who regress into autism have followed an abnormal developmental course since infancy.

MR
MR

@MaurineMeleck The one study and only study that link vaccinations to autism was fraudulent. Where is the scientific proof that links the two? There could be other factors at work, such as children being identified around/after the same time they are given vaccinations. It doesn't necessarily mean that there is any correlation between the two.

MaurineMeleck
MaurineMeleck

@MR @MaurineMeleck 

MR-sorry but there are hundreds showing the link. Please check out the C-SPAN  archives from last week(Nov. 29) and watch the Congressional Autism Hearing.  You will be enlightened, I promise.