How genetics and environment shape brain development

Roughly one in 50 Canadian children is diagnosed with autism spectrum disorder, a neurodevelopmental disorder that affects how the brain works and how people experience the world around them.

And while people with autism have extraordinary strengths and abilities, they can also encounter a wide range of challenges, depending on the severity of the disorder.

Sensitivities to bright lights and loud noises can make social events and school overwhelming. Communication difficulties can cause confusion, social anxiety, and isolation. A deep need for routine can make coping with change unfathomable. And more severe cases can result in intellectual disabilities and an inability to communicate verbally.

But what if there were a way to treat the most disabling aspects of autism so that people are better able to thrive?

That’s what UBC’s Dr. Annie Ciernia, an assistant professor in the UBC Faculty of Medicine’s Department of Biochemistry and Molecular Biology, hopes to achieve.

“It’s not about finding a cure, because autism isn’t a disease. It’s a different way of being,” she explains. “People with autism bring so much richness to society, so the question is, how can we make life easier for them?”

But in order to find effective treatments, we need to first understand how the disorder develops at the cellular level during early brain development.

To do that, Ciernia and her team at UBC are investigating how environmental factors like air pollution or inflammation can change how certain genes are expressed. This happens when environmental exposures embed themselves biologically in a person’s genes, creating chemical tags on their DNA. The chemical tags can influence whether a gene is turned “on” or “off,” leading to changes in brain development, for example.

“We know that having an infection during pregnancy can increase the risk of having a child with either autism or schizophrenia. But most people get sick during pregnancy and the majority of children are neurotypical,” she says. “So, what happens in the cases where development steers towards neurodiversity?”

The team has already identified one crucial gene that, in people with autism, can be associated with memory issues and severe learning disabilities. This gene is itself a critical regulator of how other genes are expressed in brain development and helps control how brain cells form connections.

“Once we know how genes, the brain, and the environment interact to disrupt gene expression, we can develop a potential treatment pathway,” says Ciernia.

That treatment pathway could take many different forms. It could be a medication that blocks a specific form of gene expression, or a new therapeutic that augments the areas of the brain involved in social behaviour. Or it could take the form of behaviour change, whereby people at higher risk avoid exposure to known environmental triggers.

“For example, if we know that a certain variable impacts social communication, we can focus our attention on creating targeted treatments to help those with difficulties in this area,” Ciernia explains.

“Imagine how life-changing that could be for so many people.”

But Ciernia’s ambition goes beyond advancing our understanding of the important role epigenetics plays in brain development and the neural networks involved in communication and social interaction.

She also hopes that with this knowledge we will be able to create healthier, more inclusive environments and better health outcomes.

“We’re seeing more sensory-friendly environments and events in places like theatres, airports, and children’s camps which is wonderful. And, we need to continue making inclusive environments and policies so that everyone can thrive.”