One in 68 children in the U.S. has been diagnosed with an autism spectrum disorder, according to the U.S. Centers for Disease Control — but diagnosing the disorder early is notoriously tough.
With a promising new blood test, though, diagnosing autism could get a whole lot easier, according to researchers from the University of Warwick. Those researchers said in a new study published in Molecular Autism on Feb. 18 that their test can gauge whether or not a child has an autism spectrum disorder, or ASD, with 90 percent accuracy.
Currently, doctors have to carry out a battery of time-consuming behavioral tests on children who might have the disorder, and those tests at times can be inaccurate, CNN reports. The disorder impacts 3.5 million Americans, according to the Autism Society, affecting their social interactions and communication, and causing anxiety, hyperactivity and other symptoms.
Though it’s still in the early stages, the test could lead to earlier and better treatment for children with autism, researchers said.
“Our test is expected to improve the accuracy of ASD diagnosis from 60–70 percent currently achieved by experts in neurological disorders to approximately 90 percent accuracy and potentially offered at all well-equipped hospitals with or without high level expertise in neurological disorders,” Naila Rabbani, a biologist at the University of Warwick and the study’s lead author, told Gizmodo.
Scientists at the British University found a link between the disorder and higher levels of damage to particular proteins found in the blood plasma. Working with colleagues at the University of Bologna, the British researchers found the damaged protein marker by comparing the blood and urine of 38 children with autism spectrum disorders to the blood and urine and 31 children without the disorders, they said. All the Italian children were between 5 and 12 years old.
Next, researchers hope to try the test on younger kids.
“I would really like to go forward with younger children, maybe two years, or even one year old,” Rabbani told the BBC. “Then the next step will be to validate in a larger cohort. Then the tests will be ready for screening.”
Still, some researchers are skeptical of the diagnostic method — and whether it will actually come to change how doctors diagnose the disorder.
“This study may give us clues about why autistic people are different but it does not provide a new method for diagnosis,” Dr James Cusack, director of science at the UK autism research charity Autistica, told the BBC. “It is far too early for that.”
In particular, Cusack pointed to the very small sample size used in the study.
“The best way to diagnose autism is still through clinical interview and observation,” Cusack told the BBC.
Others cautioned about the dangers of false positives. After all, the early stage blood test as it exists right now is only 90 percent accurate, according to researchers.
“[T]his is a very long way indeed from a 'test for autism,’ ” Dr. Max Davie, spokesman for the Royal College of Paediatrics and Child Health, told CNN. “It is important that it is not adopted with too much enthusiasm. If applied to a large population, it will produce large number of false positives, causing huge worry and potential harm to children and families.”
Most doctors will not diagnose a child as autistic until about 18 months old, according to the CDC, though symptoms can appear earlier. Diagnoses are considered reliable when a child is around 2 years old.
“However, many children do not receive a final diagnosis until much older,” the CDC writes. “This delay means that children with an ASD might not get the help they need.”
Autism spectrum disorder is more than four times more common among boys than among girls, according to the CDC.