Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) is a congenital and progressive neurodegenerative disorder prevalent in the French-Canadian population.
Thanks to a group of passionate volunteers from the Charlevoix-Saguenay region who dedicated their time to raising money for research, Muscular Dystrophy Canada was able to fund a research project for to investigate this rare disease. In 2008, we awarded grant funding to Dr. Bernard Brais ($325,000 over 3 years). The research project was entitled “Developing molecular, cellular and mice models for Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay.” Dr. Brais is a neurologist, co-director of the neuromuscular group of the Montreal Neurological Institute and Hospital, and Director of the CHUM ataxia centre.
In January 2012, Dr. Brais and his research team announced findings that enhance our understanding of the cellular mechanisms of ARSACS.
ARSACS is caused by genetic mutations to the SACS gene, which is responsible for producing the protein called sacsin. Dr. Brais, along with his colleagues Dr. Kalle Gehring and Dr. Peter McPherson, discovered that sacsin has a mitochondrial function in neurons. Loss of sacsin results in mitochondria that function poorly. Mitochondria — sometimes called “cellular powerplants” — convert energy into forms that are usable by the cell. The work conducted by Dr. Brais’ team revealed that the poorly functioning mitochondria led to death of the neurons, particularly in the cerebellum, a region of the brain that plays an important role in motor control.
The discovery of the central role of mitochondria in ARSACS is particularly important because mitochondrial dysfunction has been identified in other neurodegenerative diseases, such as Parkinson’s, Alzheimer’s, and Huntington’s diseases. That common link means that research being done on those other diseases may prove insightful to understanding and treating ARSACS. It also helps researchers like Dr. Brais plan new studies to continue to gain scientific knowledge in the quest of developing effective therapies for neurodegenerative diseases.
This progress towards understanding and ultimately treating ARSACS was made possible by financial support provided by several funders, including Muscular Dystrophy Canada, La Fondation de l’Ataxie de Charlevoix-Saguenay and the UK Medical Research Council.