The causes of autism remain a mystery and LinusBio is entering an ongoing and heated debate about what roles a tangle of environmental and genetic factors may play. Researchers have discovered a myriad of risk factors associated with autism, including infections during pregnancy, air pollution, and maternal stress. It has also been associated with some metal contamination, which is known to cause neurodevelopmental problems.
“All of these risk factors work in a context of genetic risk,” said Heather Volk, an associate professor in the department of mental health at the Johns Hopkins Bloomberg School of Public Health. She added that in the last 15 years, more researchers have turned their attention to environmental factors.
NBC News spoke with six independent experts from different scientific backgrounds about LinusBio’s trial. Although many were excited about the potential of the underlying science, most said caution is warranted and more research is needed. All agreed that the findings should be replicated by other teams.
“There is certainly much more work to be done before concluding that this test is a valid measure of autism spectrum disorder risk,” Dr. Scott Myers, a neurodevelopmental pediatrician at the Institute of Autism and Developmental Medicine, wrote in an email. Geisinger.
How the test works
The LinusBio test looks at the history of metabolism, telling the story of the substances or toxins the child has been exposed to over time, according to Manish Arora, the company’s co-founder and chief executive officer, who is also a professor of environmental medicine. and public. health at the Icahn School of Medicine at Mount Sinai, the academic arm of the Mount Sinai Health System. The technology was developed from research completed at Mount Sinai.
For a baby, hair can give an idea of exposures at critical times for development, such as the third trimester of pregnancy.
The test runs a laser along the length of a hair, using its energy to convert it into plasma for analysis. One centimeter, less than half an inch, of hair captures about a month’s worth of exposure data, Arora said.
Just as tree rings tell scientists about growing conditions each year, hair growth allows researchers to understand what was happening in someone’s body during specific times. LinusBio says their test can reveal metal metabolism in 4- to 6-hour increments.
“It’s almost like having a security camera that you can go back to and see four images a day,” Baccarelli said.
The technique creates huge amounts of data. That’s where a machine-learning algorithm takes over: It’s trained to look for patterns of dysregulation in metals that researchers believe are biomarkers of autism.
“We can detect the clear rhythm of autism with just one centimeter of hair,” Arora said.
Timing of Autism Diagnosis
Arora and her team hope that their technology can help young children, even newborns, receive early interventions for autism sooner than they can now.
“The problem with autism is that it is diagnosed at the age of 4 on average. At that point, a lot of Brian development has already happened,” he said. “We want to allow early intervention.”
There is still no biological test for autism spectrum disorder. Rather, children are often diagnosed after parents notice behavioral differences, such as avoiding eye contact, language delays, or failure to point. But these behaviors vary widely, and autism can also occur alongside other conditions, such as attention deficit hyperactivity disorder (ADHD), anxiety, and mood disorders.
Specialists use neurological exams, language assessments, behavioral observations, and other methods to diagnose a child. The American Academy of Pediatrics recommends autism screenings at 18 and 24 months.
Early intervention for autism typically involves individualized instruction with a trusted teacher, according to Annette Estes, director of the University of Washington Autism Center in Seattle. These programs are implemented when symptoms arise to address specific developmental needs and are often game-like.
“Babies are little scientists. They are testing things and looking for feedback,” she said. «You can really accelerate development in all children.»
But little is known about the effect that presymptomatic intervention might have for young children at increased risk of autism.
«We have theories about what we could do,» Estes said, «but it hasn’t been studied very much.»
Next steps, more data
The Food and Drug Administration gave the LinusBio test a «breakthrough» designation, which is intended to speed up the regulatory approval process of new technologies when there are no alternatives on the market. The designation does not change approval standards, and the company faces regulatory hurdles before its device can be considered for widespread use in the US.
In the published study, the researchers trained and tested their technology by evaluating hair samples from 486 children in three countries: Japan, Sweden, and the United States.
In an analysis of 97 hair samples, the algorithm correctly identified cases where an autism spectrum disorder was diagnosed more than 96% of the time. Correctly identified negative cases approximately 75% of the time. The evaluated group included 28 cases of autism, a much higher proportion than in the general population.
«This needs to be repeated for larger sample sizes and a larger data set,» Volk said.
The company, which has raised more than $16 million in venture capital investments, is working on an expanded study and has collected samples and data on a group of about 2,000 people.
Because the predictive value of a test depends on the prevalence of a condition in the group being tested, the test’s accuracy would decrease in a general population, where autism rates hover around 2%.
That’s part of the reason the LinusBio team sees the tool as merely helping doctors reach a diagnosis.
«No doctor should make a decision about whether a child has autism based solely on this,» Arora said. «This provides crucial information, but not the only one.»
The test might be more useful in groups with a higher risk of autism, such as children who have no developmental markers or have siblings with autism.
The researchers also believe that precision could be improved by repeated testing, analyzing and comparing multiple strands of a child’s hair.
However, from Estes’s perspective, no test or technology can address the biggest and most important barrier for families of children seeking care for autism: finding trained doctors who can make a specialized diagnosis and building a care team for the autism. infant. Many parents can’t get help even if they notice developmental delays, she said.
“Early intervention is something most kids don’t have access to right now,” Estes said. “We know how to help children. It’s very difficult to get access.»
Arora hopes that in the future, new technology may also provide clues about what is changing in a child’s body when autism manifests itself. Perhaps eventually, that information could open new avenues for the development of autism drugs or therapies, she said.
LinusBio said it also plans to apply the approach to other health conditions with known links to environmental factors, including Lou Gehrig’s disease, or ALS, gastric disorders and certain types of cancer.