What is ARSACS?

ARSACS is the common name for Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay. It is a progressive disease that affects the body's ability to create a protein called sacsin, normally found in the brain, skin, and muscles.

The first symptom, unsteady gait, typically appears between 12 and 18 months of age as toddlers begin to walk. Children also develop speech problems due to weak neck and facial muscles. The condition becomes increasingly worse over time, with muscle tension and spasms, difficulty coordinating movements, involuntary eye movements, and muscle wasting. Some people with ARSACS also lose sensation in their arms and legs as the nerves degenerate.

Other symptoms include incontinence, deformities of the fingers and feet, and buildup of fatty tissue on the retina leading to vision problems. Occasionally, the disease also causes leaks in one of the valves that control blood flow through the heart.

Most people with the condition are usually of normal intelligence and are able to live independently well into adulthood, although they eventually lose the ability to walk.

How common is ARSACS?

The majority of people with ARSACS have ancestry in the Charlevoix-Saguenay region of Quebec, Canada, where the condition affects approximately 1 in 1,500 to 2,000 people. Elsewhere in the world, the condition is rare.

How is ARSACS treated?

Treatment for ARSACS focuses on easing the symptoms and postponing major functional disabilities. Physical therapy and anti-spasmodic oral medications can help control muscle spasms, prevent joint and tendon deformities, and preserve muscle function for some time. Low doses of medication can control incontinence. Occupational therapy and adaptive tools such as leg braces can support people with ARSACS in daily tasks such as driving. As the disease progresses, however, people with ARSACS typically lose the ability to perform these tasks. Children with the condition may benefit from speech therapy and other forms of support in school.

What is the prognosis for a person with ARSACS?

People with ARSACS become wheelchair-bound at an average age of 41 and commonly die in their fifties.