Developers of an experimental blood test for autism say it can detect the condition in more than 96 percent of cases and do so across a broad spectrum of patients, potentially allowing for earlier diagnosis, according to a study released on Thursday.
The findings, published in PLoS Computational Biology, are the latest effort to develop a blood test for autism spectrum disorder, which is estimated to affect about 1 in 68 babies. The cause remains a mystery although it has been shown that childhood vaccines are not responsible.
The hope for such tests, if proven accurate, is that they could reassure parents with autism fears and possibly aid in the development of treatments, coauthor to the study, Dr. Juergen Hahn of Rensselaer Polytechnic Institute, told Reuters Health.
They could also speed the age at diagnosis. Autism encompasses a wide spectrum of disorders, ranging from profound inability to communicate and mental retardation to relatively mild symptoms, as in Asperger's Syndrome.
Doctors typically diagnose children by observing behaviors associated with the disorder, such as repetitive behaviors or social avoidance. Most children are not diagnosed until around age 4, although some skilled clinicians can pick it up earlier.
Hahn and colleagues measured levels of 24 proteins that have been linked to autism and found five that, in the right combination, seemed most predictive of the condition, which affects about 1.5 percent of children and can vary widely in severity and how it manifests.
Dr. Max Wiznitzer of the University Hospitals Cleveland Medical Center, who was not involved in the research, called the finding "interesting, but not earth-shattering," saying that it needs to be tested by many more at-risk children.
"We don't know if this is a marker specific to autism or whether it's a marker for any chronic illness of any kind," he told Reuters Health. "They have quite a way to go before they can show if it has any meaning."
The researchers derived the combination by testing 83 children age 3 to 10 who had been diagnosed with autism through conventional means. While the combination was present in 97.6 percent, it was absent in 96.1 percent of 76 normal children.
Wiznitzer noted that the research offers no evidence that the chemical combination being blamed for autism "will be there for infants and toddlers."