Autosomal recessive ataxia of Charlevoix Saguenay (ARSACS) is a rare genetic disorder that affects the nervous system. It is characterized by progressive impairment of coordination, balance, and speech. The disease is named after the region in Quebec, Canada where it was first identified in a large family. The prevalence of ARSACS is highest in this region, with an estimated incidence of 1 in 3000-5000 individuals. It is now the second most prevalent form of ataxia worldwide
The most common clinical features of ARSACS include difficulty walking, frequent falls, tremors, muscle weakness, and slurred speech. The disease usually begins in childhood or adolescence and progresses over time. Other symptoms may include vision problems, hearing loss, and reduced sensation in the limbs. Patients may also experience cognitive impairment, including difficulty with memory, attention, and problem-solving.
ARSACS is inherited in an autosomal recessive pattern. This means that a person must inherit two copies of the defective gene, one from each parent, in order to develop the disease. Individuals who inherit only one copy of the gene are called carriers, and do not usually experience any symptoms. When two carriers have children, there is a 25% chance that each child will inherit two copies of the gene and develop ARSACS.