UNC scientists publish findings linking autism and environment

Scientists from UNC’s School of Medicine have discovered a link between autism and environmental factors — and it all started over a longstanding lunch date.

Mark Zylka and Ben Philpot, researchers in the Department of Cell Biology and Physiology, said their research began as a collaborative effort about three years ago after one of their many mealtime conversations.

Philpot convinced Zylka to join his work on Angelman syndrome, a rare neurogenetic disorder.

Nature, an international journal of science, published the work of Philpot, Zylka and their team of researchers in its Thursday issue. The paper details the team’s work about a potential environmental cause of autism.

“Nature is kind of the pinnacle of journals we can publish in, and to have that kind of exposure, it will only bring better people to UNC, both graduate students and postdocs,” Philpot said.

UNC ranked second internationally among institutions publishing autism research in 2010, trailing only Harvard, Zylka said.

Ian King, a postdoctoral student in the School of Medicine, said the team stumbled upon the discovery when they tested the potential for topotecan to relieve the symptoms of Angelman syndrome.

Zylka said topotecan, a drug often used in chemotherapy, can be utilized to inhibit topoisomerase, an enzyme, which in turn limits the expression of certain genes.

The genes limited by topotecan were particularly long, a characteristic shared by genes linked to autism.

Zylka said the suppression of these genes by topotecan and other topoisomerase inhibitors, which may be present in the environment, could affect brain development in a manner that results in autism.

This “eureka” moment left the researchers with an unforgettable feeling, Philpot said.

“You take something that’s been around for 40 years and you assume a lot of people know about it and then we came into the field and made a discovery no one else had made,” Zylka said.

King, who conducted many of the experiments in the study, said the efforts going forward will be directed toward finding other drugs that have similar properties to topotecan.

Better understanding of the drugs could help doctors advise pregnant women to avoid certain environmental factors that may increase the chances of autism, King said.

Diagnoses have increased over the past decade.

Given the complexity of autism’s causes, if this discovery applies in just 1 or 2 percent of autism cases, it would be significant, King said.

Even with advances like this being made, there is still a lot of work to be done in understanding the causes of autism, said James Collier, the advocacy chair for UNC’s chapter of Autism Speaks, an autism science and advocacy organization.

“This is still a condition that we’re sorting out all the rules of,” he said. “We just don’t know a ton about it yet.”

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