A breakthrough autism study finds a surprising clue in children's mouths
any health condition requiring special care beckons us to ask why it happened. Understand the cause, and we’re closer to solving the problem. So it is with autism spectrum disorder (ASD), which currently affects about one in 59 children—a jump from one in 150 children in 2000. That increase has led to a frenzied desire to find a cure.
A new study focused on baby teeth offers some promise. Researchers at the Icahn School of Medicine at Mount Sinai wanted to examine how children process essential nutrients delivered in the womb. Before a child is born, his or her teeth grow new layers each day, and the layers record the elements wending their way through the body, much like tree rings. Paul Curtin, who works in environmental medicine, and his team suspected the layers could reveal whether kids on the autism spectrum metabolize chemicals differently.
The researchers collected teeth from kids with and without ASD, used lasers to isolate single layers and examined the levels of copper and zinc during the second and third trimesters. “When metabolism of zinc and copper is dysregulated,” explains Curtin, “it can lead to disease.”
According to their report, published in May in Science Advances, children with autism processed the two metals very differently. Just by looking at how they were metabolized, the researchers could predict which teeth belonged to children with ASD. They could even spot the difference between autistic and nonautistic siblings.
Exactly why children with ASD metabolize zinc and copper abnormally is unknown. “That’s the focus of future work,” says Curtin. But the researchers hope that the finding could lead to a new diagnostic tool, one that could identify autistic children at a younger age than is now possible. “One challenge is that we haven’t had any biological markers of autism,” says Curtin, referring to current tests, which focus on behavior and cognition, producing vague results that are subject to interpretation. Tissue for zinc and copper metabolism would provide a more objective measure.
Curtin stresses that these results do not explain the cause of autism or the recent increase in the number of children on the spectrum. But it’s an excellent opening clue.