Recently I’ve had a ton of press releases come across my laptop about new developments in autism screening. A Harvard researcher says he’s found a way to identify kids with autism with just seven short questions and a home video clip. A genetics lab says it can identify genetic markers in toddlers at higher risk for autism, because they have siblings on the spectrum. A different lab say it can identify genetic markers for autism in “pre-implementation genetic diagnosis” during the in vitro fertilization process.
Parents often wait months to have their children evaluated when autism is suspected, so these tests might sound pretty tempting. But how many of them are evidence-based and scientifically valid?
I interviewed one of the world’s leading autism researchers and clinicians, Dr. Catherine Lord, who led the development of tools that have become the gold standard for diagnosis: the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview – Revised (ADI-R). Dr. Lord is the Director of the Center for Autism and the Developing Brain at New York-Presbyterian Presbyterian Hospital, Weill Cornell Medical College and Columbia University Medical Center.
On the one hand, you could figure that having developed the gold standard tests, maybe she’s biased, but on the other hand, this woman really knows what the hell she’s talking about. I was thrilled that she took time out of her busy day to speak with me and help translate some of the medical lingo into usable information for parents.
What’s the deal with “microarray” prenatal testing for autism markers?
A Chicago company called Reproductive Genetics Institute offers “24-chromosome microarray testing” which can supposedly identify autism before a an embryo is implanted during the in vitro fertilization process. So, it’s clearly not a super-creepy eugenics thing, right? Of course not! RGI’s press release quotes Dr. Norman Ginsberg (without mentioning that he works for RGI) as saying,
“Knowing that your child has a genetic condition, whether it be Williams Syndrome or Autism, will allow the parents to begin early intervention and proper treatment, as opposed to spending valuable time and resources chasing down an accurate diagnosis.”
Not surprisingly, Dr. Lee Shulman, Clinical Director at Reproductive Genetics Institute, recommends the microarray-based testing (which costs about $4,000) for anyone expecting a child. “The genetic abnormalities identified through aCGH are irrespective of age,” says Dr. Shulman. “This technique will offer more accurate information on the pregnancy.”
Is any of this real? Dr. Lord noted that in a study of 2,700 children with autism, the biggest genetic finding was found in a whopping eleven children.
“Where we are right now is that there have been many, many different areas on the chromosome that have been found to be associated on some level with autism,” Dr. Lord said. “The problem is that many of those areas on the chromosomes may be associated with a learning disability, or a language delay that turns out to be just fine.”
Dr. Lord cautioned parents that the 24-chromosome microarray test “is not a genetic assessment that is approved by National Institutes of Health, the American Academy of Pediatrics, or the majority of scientists. These are entruprenuers who have quite creatively said if you happen to have these combinations, then your risk for autism is higher. The problem is that most cases with autism at this point have not been associated with any genetic finding.”
“If the test does find something, to conclude that this child will have autism is not accurate. If you have these tests and nothing comes up, you still can’t say this child will not have autism. What makes more sense for families that are concerned is to consider family history. That’s the number one predictor, besides being male. Having a sibling with autism increases the likelihood by 10 to 20 percent. So even then, the majority of subsequent children will not have autism.”
What’s the deal with genetic screenings for toddlers?
French biotech company IntraGen, which has its U.S. base in Cambridge, Mass., says its ARisk Assessment Test is “a gender specific, genetic screening test that looks at 65 genetic markers associated with Autism Spectrum Disorder (ASD).” The ARisk is for children aged 6 months to 30 months with siblings on the autism spectrum, but IntraGen says a similar test for all children is in the works. The company notes that the M-CHAT (Modified Checklist for Autism in Toddlers) screening tool recommended by the American Academy of Pediatrics for use in toddlers is only valid for children 16 months and older.
I asked Dr. Lord if parents who were concerned about their toddlers wouldn’t be better served by, you know, just having them evaluated for autism?
“If you’ve got a toddler and you’re worried,” said Dr. Lord, “take the toddler to someone who knows about autism. Get information about whatever it is the child is doing.”
Dr. Lord pointed out that there are a number of different screening tools for pediatricians to choose from. The M-CHAT is recommended for children at the 18-month and 24-month well visits. She cautioned, however, that ”just using the M-CHAT questionnaire does not work. If a pediatrician is going to use that, then if they get a positive, someone has to go back and go over the form with the parent, and get a sense of how the parent interpreted the questions.”
Another screening tool is the Ages & Stages Questionnaire, which looks at general child development. This test helps identify delays in children from one month to age five and a half. Dr. Lord also recommended the Infant-Toddler Checklist, which is not specific to autism, but does look at the child’s communication skills.
“It’s quite good at identifying not only kids with ASD but with any kind of communication disorder,” Dr. Lord said.
Dr. Lord also emphasized that a parent’s concern is the most critical factor. “If a parent is worried that their child is losing skills, or is not responsive, or is not interested in other people, that should be taken seriously.”
Are any of the genetic tests valuable?
“There are certain genetic syndromes like Fragile X that have a higher risk for autism. Beyond that,” said Dr. Lord, “we’re just beginning.”
“We hope that as we begin to chip away at these specific genetic findings, we’ll learn more. So far, many of them are not inherited. They’re de novo, or new, mutations. We hope that as we begin to get a better sense of when these findings are truly associated with autism, we’ll be able to tell families. But we aren’t there yet. Even in families with two children with autism, some of them have different genetic patterns.”
How about this quick screening test coming out of Harvard?
Harvard University researcher Dennis P. Wall says he has developed a web-based toolthat accurately screens for autism within minutes, combining computer algorithms, a seven-point parent questionnaire, and a home video clip of the child playing. TIMEMagazine reports that some autism experts are “so skeptical they’re not even willing to speak on the record about it,” which makes approximately zero sense to me. If it’s that bad an idea, why is anyone afraid to comment on it?
Turns out Dr. Lord is definitively not afraid to comment.
“It’s just garbage,” she said. When looking at the effectiveness of screening tools for autism, “you’ve got to deal with specificity.” In testing, sensitivity measures the proportion of actual positives which are correctly identified as such (e.g. the percentage of people who are correctly identified as having the condition). Specificity measures the proportion of negatives which are correctly identified (e.g. the percentage of healthy people who are correctly identified as not having the condition).
“There’s no benefit to this particular screening technique, if you’re going to over-identify by 500 percent. We need to help people get started, but we need to do it in a formal way.”
Dr. Lord notes that some current evaluation tools, like the Social Responsiveness Scale (SRS) parent questionnaire, also over-identify autism, but not to this degree.
I asked Dr. Lord if there wasn’t some benefit to making a quicker screening tool available, given that it took over a year to have my 10-year-old daughter diagnosed with autism.
“Yes, but you want it to be sensitive. You can’t over-identify to this degree, or it becomes completely invalid,” Dr. Lord said. “It would be great if there was some simple screening. It’s very difficult.”
Dr. Wall disagrees, and says his test measures up against the “gold standard” tests. He also argues that quicker screening tools are essential to getting kids diagnosed and beginning treatment at a younger age. He told TIME Magazine that “our goal is to bridge the gap and take [the evaluation time] from 18 months to days. The gold standard tests take too much time. We need tests that are as good but can be administered at a rate that scales with the increasing size of the population that’s at risk.”
Are the ADOS and ADI-R still the gold standard?
Dr. Lord said the ADI-R is used mostly for research, although a shorter version is in the works. The ADOS is used most often in the clinical setting, to actually identify children on the autism spectrum. She says it appeals to clinicians for a number of reasons, but primarily because it helps identify not only areas where the child is struggling, but areas where the child may be doing very well.
“The reality is that clinically, the ADOS is used the most. It’s faster (one hour) . If you have a child with a constellation of difficulties, you want someone to give you feedback on where they’re struggling and what they’re good at.”
The ADOS is designed to help clinicians make recommendations on ways to help the child overcome delays and capitalize on strengths.
“Families need to focus less on the diagnosis, and more on what to do about it,” Dr. Lord said. “The label provides you a base. But the reality is that what you want is for someone to say, ‘this is something not to worry about,’ or ‘this is something we want to work on.’ You want to help that child use their strengths just as much as you want to help them where they’re struggling.”
(Photo Credit: iStockphoto)
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