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New test for autism hopes to help doctors diagnose before symptoms appear

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The causes of autism remain mysterious and LinusBio enters into an ongoing and heated debate about the roles that a tangle of environmental and genetic factors can play. Researchers have found a myriad of risk factors associated with autism, including infections during pregnancy, air pollution and maternal stress. Some metal pollution, known to cause neurodevelopmental problems, has also been associated with it.

“These risk factors all operate against a background of genetic risk,” said Heather Volk, associate professor in the Department of Mental Health at the Johns Hopkins Bloomberg School of Public Health. She added that over the past 15 years, more researchers have turned their attention to environmental factors.

NBC News spoke to six independent experts from different scientific backgrounds about LinusBio’s test. Although many were excited about the potential of the science behind it, most said caution was in order and more research was needed. All agreed that the results should be replicated by other teams.

“There is certainly still a lot of work to do before we conclude that this test is a valid measure of risk for autism spectrum disorder,” said Dr. Scott Myers, neurodevelopmental pediatrician at the Geisinger Autism & Developmental Medicine Institute, said. written in an email.

How the test works

The LinusBio test analyzes metabolic history, telling the story of substances or toxins the child has been exposed to over time, according to Manish Arora, co-founder and CEO of the company, 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 done at Mount Sinai.

For an infant, hair can provide insight into exposures at critical developmental times, such as the third trimester of pregnancy.

The test runs a laser the length of a hair, using its energy to turn it into plasma for analysis. One centimeter — less than half an inch — of hair captures about a month of exposure data, Arora said.

Like a tree’s rings tell scientists about growing conditions each year, hair growth allows researchers to understand what was going on in a person’s body at specific times. LinusBio says its test can reveal metal metabolism in 4 to 6 hour increments.

“It’s almost like having a security camera where you can go back and see four images a day,” Baccarelli said.

The technique creates huge amounts of data. This is where a machine learning algorithm takes over – it’s trained to look for patterns of metal dysregulation that the researchers say are biomarkers of autism.

“We can detect the clear rhythm of autism with only about a centimeter of hair,” Arora said.

Timing of Autism Diagnosis

Arora and her team hope their technology can help young children, even newborns, receive early intervention for autism sooner than they currently can.

“The problem with autism is that it is diagnosed at the average age of 4. By then, so much brain development has already happened,” he said. “We want to enable early intervention.”

A biological test for autism spectrum disorders does not yet exist. Rather, children are often diagnosed after parents notice behavioral differences, such as avoiding eye contact, language delays, or not pointing. 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 months and 24 months.

Early intervention for autism usually involves one-on-one 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 appear to address specific developmental needs and are often game-like.

Babies are little scientists. They try things out and seek feedback,” she said. “You can really accelerate the development of all children.”

But little is known about the effect that pre-symptomatic intervention might have on young children at higher risk for autism.

“We have theories about what we could do,” Estes said, “but it hasn’t been studied extensively.”

Next steps, more data

The Food and Drug Administration has given LinusBio’s test a “breakthrough” designation, which is to expedite the regulatory approval process for 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 United States.

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 in which autism spectrum disorder was diagnosed more than 96% of the time. It correctly identified negative cases about 75% of the time. The group tested included 28 cases of autism, a much higher proportion than in a general population.

Manish Arora.
Manish Arora.LinusBio

“It needs to be repeated on larger samples and a larger dataset,” Volk said.

The company, which has raised over $16 million in venture capital investment, is working on an in-depth study and collecting samples and data from a group of around 2,000 people.

Since the predictive value of a test depends on the prevalence of a condition in the group being tested, the accuracy of the test would be diminished in a general population, where autism rates are around 2%.

This is partly why the LinusBio team sees the tool as simply helping clinicians arrive at a diagnosis.

“No clinician should decide if a child has autism based on this alone,” Arora said. “It provides crucial information, but not the only information.”

The test might be more useful in groups at higher risk for autism, such as children who missed developmental markers or have autistic siblings.

The researchers also think accuracy could be improved with repeated testing – analyzing and comparing multiple strands of a child’s hair.

However, from Estes’ perspective, no test or technology can solve the biggest and most important hurdle for families of children seeking care for autism: finding trained clinicians who can make a specialized diagnosis and build a care team for the child. Many parents cannot get help even if they notice developmental delays, she said.

“Intervening in time is something that most kids don’t have access to right now,” Estes said. We know how to help children. It’s really hard to get there. »

Arora hopes that in the future, new technology may also provide clues about what changes in a child’s body as autism manifests. Perhaps ultimately, this information could open up new avenues for the development of drugs or therapies for autism, he said.

LinusBio said he 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 cancers.

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