From Sleep Disorders to Parkinson’s disease

When people develop REM sleep behaviour disorder, where they act out their dreams in their sleep, it’s often a precursor to an even more serious illness.

Up to 80 percent of people with this disorder later develop Parkinson’s disease, Lewy body disorder or, more rarely, multiple system atrophy. That’s why identifying those at risk of having the sleep disorder, known as RBD, would also flag those at risk for the other neurodegenerative illnesses.

At McGill University, geneticist and neuroscientist Lynne Krohn, a PhD student, is screening genes to find those that increase the risk of RBD. So far, she’s found five genes that make people more susceptible when the genes are mutated, or damaged.

“These same genes are also implicated in Parkinson’s disease risk,” Krohn says.

“The over-arching goal is better treatment of Parkinson’s disease.”

Using blood and DNA samples from volunteers diagnosed with RBD who are at risk of converting to neurodegenerative diseases, Krohn will screen the samples for these genes.

She’ll then compare them with samples from people who are healthy, and create a polygenic risk score. She hopes that score will predict who is most likely to develop RBD, and subsequently, how fast RBD might convert to one of the other neurodegenerative disorders.

“We have evidence that these genetic mutations are affecting how fast people develop Parkinson’s disease or Lewy body dementia or, in some cases, multiple system atrophy, once they already have RBD,” Krohn says.

Having this risk information early, before someone has symptoms of one of these diseases, could ultimately help them enroll in clinical trials of new drugs or therapies. Eventually, Krohn hopes knowing people’s risk for these diseases will also help them get treatments before their brains have been severely damaged.

“The overarching goal is better treatment of Parkinson’s disease,” she says.

Krohn’s decision to pursue a career in research came when she was working in the music industry in New York City and teaching yoga.

She was reading The Brain that Changes Itself by Norman Doidge and The Mind and the Brain: Neuroplasticity and the Power of Mental Force by Jeffrey Schwartz and Sharon Begley, when she met a neurologist who was one of her yoga clients. After their conversations, he encouraged her to switch fields and do her own research on the brain.

She began by working as a research assistant at Columbia University before going back to university herself at 26.

“I thought that the RBD story, the fact that it’s an early target for something that is so hard to treat like Parkinson’s, is fascinating,” Krohn says.