Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS): a once obscure neurodegenerative disease with increasing significance for neurological research

Background: Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) is a rare cerebellar ataxia occurring in the Charlevoix-Saguenay population in Quebec with high incidence as a result of founder effects. Following the discovery of the gene responsible for the disease, many other patient groups have been identified worldwide and the characterization of the gene product, sacsin, has unveiled similarities between the pathogenic mechanism of ARSACS and those of other major neurodegenerative disease. Summary: The core symptoms of ARSACS consist of a triad of early-onset cerebellar ataxia, peripheral neuropathy and spasticity, which is accounted by degeneration of Purkinje neurons. The gene responsible for the disease is located on chromosome 13q11 and encodes for the chaperone sacsin. Drp-1, a GTPase crucial for regulating mitochondrial fission/fusion dynamics, has been identified as a potential substrate of sacsin, suggesting a link between the pathogenic mechanisms of ARSACS and prevalent neurodegenerative diseases such as Alzheimer’s, Parkinson’s and Huntington’s diseases.