Can a saliva test detect autism spectrum disorder?
Autism spectrum disorder, or ASD, is a developmental disorder that has traditionally been detected through behavioral screening. The Center for Disease Control and Prevention (CDC) recommends that children be screened for developmental delays and disabilities, such as autism, at regular well-child doctor visits as young as 9 months old. Children should be specifically screened for autism spectrum disorder at 18 and 24 month checkups, too. The CDC even says “additional screening might be needed if a child is at high risk for ASD or if behaviors sometimes associated with ASD are present.” There is now a saliva test that can help identify autism in children.
Currently, the screening process for autism spectrum disorder has a lot of time-consuming steps, and they’re all behavioral based.
The first step for an autism screening could be a simple questionnaire. Some of these questionnaires are for the parents to fill out, and others are assessments done by the child’s doctor. One of the most common screening tests are the Modified Checklist for Autism in Toddlers, otherwise known at the M-CHAT. This test asks questions about behaviors that typically point toward autism spectrum disorder. However, the issue with this test is it has a very high sensitivity level. That means, a lot of children are being indicated as having ASD, when they actually have a separate developmental disorder, or none at all.
The second step of diagnosis could be a comprehensive diagnostic evaluation. The CDC explains “this thorough review may include looking at the child’s behavior and development and interviewing the parents. It may also include a hearing and vision screening, genetic testing, neurological testing, and other medical testing.”
In most cases, the child’s doctor will refer the child to a specialist to complete this step. These specialists could be developmental pediatricians, child neurologists, or child psychologists/psychiatrists. Since the ratio of specialists to primary care physicians is much smaller, this causes a huge backup in the diagnostic funnel. Rather than just kids who have autism spectrum disorder being sent to see specialists to make the official diagnosis, it’s children who are developing typically, or have different developmental disabilities altogether.
Overall, the issue with the current way of practice is that all of the tests for ASD are subjective and behavioral. They are based on an individual’s perception, rather than something objectively biological, like a saliva test. Not to mention, various factors could take place in the appointment that could impact a child’s diagnostic fate.
Not to mention, there are variable in every appointment to consider.
In 2006, the American Academy of Pediatrics conducted a study and learned that the average visit at your pediatricians lasted 18 minutes. A separate study in 2007 revealed that “very limited amount of time was dedicated to specific topics in office visits.” In fact, typically six different topics were covered in a short visit of 15 minutes. The study says that the longest topic was spent being discussed for five minutes, where as the others were on average of one. At best, that’s only five minutes spent talking about autism spectrum disorder.
Appointments with specialists don’t always prove to be effective, either, due to the child being thrown in an unusual environment. Olivia, a mom of a young boy with autism, speaks to her experiences having her son diagnosed with ASD.
“My son, Jackson, was diagnosed with autism at 2 and a half,” she explained.
“When Jackson was tested and diagnosed, we met with a group of professionals who evaluated him for about three hours. But I felt during the evaluation that Jackson wasn’t in his environment. He was in a new place with people that he had never met before and I knew he could do some of the things they were asking him to do. But because of this new space and these new people, he wasn’t doing some of the things they were asking him.”
“Having a saliva test is more scientific, more definitive. There was a more concrete answer. And instead of taking 3 hours to do the test and Jackson having a tantrum the whole time, it was a squick cheek swab and it was over within minutes,” she explained.
There are miRNA in the saliva that can accurately distinguish autism spectrum disorder from other developmental delays.
Well, not exactly. Clarifi is an epigenetic test. That means it looks at RNA, rather than DNA, like a genetic test would.
Our research discovered that specific microRNAs, as well as other types of non-coding RNAs that are found in the saliva of children with autism were different than the RNA found in the saliva of typically developing children, or children with other kinds of developmental delays, like ADHD, for example.
The key RNA categories we look at include lncRNA, piRNA, miRNA, and the microbiome. These RNA are involved in a wide range of biological processes in the body, which makes them a robust source of biomarkers for autism.
Basically, there’s a lot going on in your spit!
Saliva provides a better way to detect autism because it’s easy and painless to collect, it’s stable at room temperatures, and it contains high concentrations of these RNAs. Saliva provides a noninvasive way to assess biology underlying brain function, which gives us a great look into autism spectrum disorder.
While the current way of diagnostics shouldn’t be thrown out the window, this autism saliva test could be a great addition to already used tactics. This tool could give primary care doctors the power to diagnose autism, or help funnel which patients actually should be sent to specialists, and which patients could just start services for autism without waiting in a long specialist line.
This is an objective tool for autism spectrum disorder that could help change the diagnostic timeline for families across the country. Clarifi is the first to measure non-coding RNA in saliva as an autism diagnostic aid.