Parkinson Canada had the pleasure of sponsoring and attending the first ever international meeting focused on GBA1. Held at the Montreal Neurological Institute-Hospital, also known as The Neuro, in Montréal from June 27th to 29th, the meeting hosted several excellent researchers, clinicians, trainees and representatives from industry to discuss new findings on the role of GBA1 in Parkinson’s disease (PD).
GBA1, a gene that encodes the enzyme glucocerebrosidase (GCase), is host to several genetic variants that are known to increase one’s risk of developing PD. In fact, mutations in GBA1 are the most common genetic risk factor for PD, making it an important focus for many researchers. Intriguingly, mutations in GBA1 can also cause Gaucher disease, which is when lipids (fats) accumulate in certain organs, particularly the liver and spleen, which can cause reduced organ function. Ongoing research into the role GBA1 plays in PD, specifically how symptoms and disease progression change over time, is critical to clinical management of at-risk individuals and developing the appropriate treatment approaches for GBA1 mutation carriers. Hence, the meeting was an important first step in sharing knowledge and forming collaborations to move this area of study forward. It was also encouraging to see that this effort was led by Canadian Parkinson’s genetics expert Dr. Ziv Gan-Or from the Neuro.
On day 1, we heard from important researchers in the field of GBA1 biology discuss the mechanisms of GBA1-associated neurodegeneration and the metabolic pathways associated with GCase dysfunction. Gaining a better understanding of the underlying biology of disease can lead to better biomarker discovery and alternative routes for therapeutic development. We learned about how in GBA1-PD there may be dysfunctional activity of the mitochondria, an important part of the cell that provides energy for everyday cellular processes, and that altered GCase activity can lead to an accumulation of aggregated alpha-synuclein. We also heard that there may be an interplay between GBA1 and LRRK2, another PD-associated gene. The day ended with a data blitz session that highlighted candidates for future GBA1 therapeutics and insightful talks on how sex and ancestry play a larger role in disease development, symptom progression, and medical management of disease.
On day 2, we learned more about the genetics of GBA1-PD, specifically the prevalence of different GBA1 mutations amongst people of different ancestries. These discussions are important to consider when planning population-based research as our current landscape of data heavily favours people of European ancestry. Future work needs to be done to enhance the level of non-European research to better reflect the worldwide population. In the afternoon, we learned about how GBA1 mutations can be classified to determine if a disease course of PD may be mild or severe depending on the mutation, as well as the clinical presentations of GBA1-PD, which typically includes REM sleep behaviour disorder (RBD) and/or hyposmia (lost sense of smell) years before a PD diagnosis. We discussed different methods to identify and detect PD at these earlier timepoints in disease progression, and how initiatives like G‑CAN, a multidisciplinary, Canadian-led international platform to study GBA1, will aid in the acceleration of biomarker and therapeutic development.
On day 3, we began the day with a data blitz session, hearing from several experts in the field on how lipids change in GBA1 mutation carriers, as well as the results from a 15-year longitudinal study of people at risk for developing Gaucher disease or PD, and several groups that are aiming to develop disease‑modifying therapies. The remainder of the day was focused on clinical trials for GBA1-PD taking place around the world. Since it is generally considered that GBA1 mutations largely result in a loss of GCase function, leading to a buildup of lipids, several therapies are being developed to boost GCase activity, resulting in less lipid accumulation and reduced or slowed neurodegeneration. We learned about therapies targeting the supplement of GCase through repurposing old drugs like Ambroxol, gene therapy which aims to replace or fix a faulty gene, anti‑sense oligonucleotides (ASOs), and targeting compounds that can fix GCase function. Encouragingly, several of these clinical trials are in phases 2 and 3. In Canada, there are currently 2 clinical trials targeting GBA1-PD that are recruiting participants, including a phase 2 clinical trial using a small molecule to increase GCase activity, and a phase 1/2 clinical trial using MRI-guided focused ultrasound to enable more GCase to enter the brain to increase its activity. While all of these trials are encouraging to the field, it was also suggested for clinical trial groups to work together to reduce redundancy of trials, increase cohort size, and target specific GBA1 mutations to yield more confident, translatable results.
Several posters were presented at the meeting, including Canadian researcher, Maxime Teixeira, from Université Laval, who was awarded 1st place in the trainee abstract competition. Maxime presented his work studying the dynamics of alpha-synuclein aggregation in PD by generating a new model to watch alpha-synuclein aggregate in real time to better understand the role it plays in disease. Awarded 2nd place was Parkinson Canada Graduate Student Awardee Emma Somerville from McGill University. Emma presented her work investigating the genetics behind lipid accumulation in PD with the goal of garnering a more complete understanding of the intricate interplay between genetics, lipid metabolism, and PD.
When asked about her favourite aspect of the GBA1 Meeting, Emma emphasized her excitement for the collaborations and new connections that were made. Indeed, there were several opportunities for networking and Emma is looking forward to seeing what comes of these collaborations in the future.
Parkinson Canada was proud to sponsor the GBA1 Meeting and continues to fund groundbreaking research in Canada across all areas of PD including genetics. In the most recent Annual Research Competition, a Pilot Project Grant was awarded to Dr. Chris Phenix at the University of Saskatchewan to develop novel, highly sensitive tools that can measure GCase activity in the blood and saliva. Parkinson Canada is also partnering with the Michael J Fox Foundation and Cure Parkinson’s in advising the G-Can initiative as members of the Steering Committee and as research funders who have an important role to play in driving this work forward.
We look forward to hearing the exciting updates from everyone at the next meeting and to continue supporting forums such as these which bring together scientists, clinicians, industry, and patient organizations from around the world to discuss important topics in PD.