Autosomal recessive spastic ataxia of Charlevoix-Saguenay

Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) is a rare genetic disorder characterized by a combination of spasticity, ataxia, and peripheral neuropathy. It was first identified in the Charlevoix and Saguenay-Lac-Saint-Jean regions of Quebec, Canada.

Clinical Features

ARSACS is primarily characterized by the following clinical features:

• Spasticity: Increased muscle tone leading to stiffness and difficulty in movement.
• Ataxia: Lack of voluntary coordination of muscle movements, often resulting in gait abnormalities.
• Peripheral Neuropathy: Damage to the peripheral nerves causing weakness and sensory loss.

Other symptoms may include dysarthria, nystagmus, and retinal hypermyelination.

Genetics

ARSACS is inherited in an autosomal recessive manner. This means that an individual must inherit two copies of the mutated gene, one from each parent, to be affected by the disease. The gene associated with ARSACS is the SACS gene, which encodes sacsin, a protein involved in maintaining the integrity of the cytoskeleton.

Diagnosis

Diagnosis of ARSACS is based on clinical evaluation, family history, and genetic testing. MRI findings often show atrophy of the superior cerebellar vermis and increased signal intensity in the pons and middle cerebellar peduncles.

Management

There is currently no cure for ARSACS. Management focuses on symptomatic treatment and supportive care, including:

• Physical Therapy: To improve mobility and reduce spasticity.
• Occupational Therapy: To assist with daily living activities.
• Speech Therapy: To address speech difficulties.

Epidemiology

ARSACS is most prevalent in the Charlevoix and Saguenay-Lac-Saint-Jean regions of Quebec, with a carrier frequency of 1 in 22. However, cases have been reported worldwide.

Research

Ongoing research aims to better understand the pathophysiology of ARSACS and develop potential therapies. Studies are exploring the role of sacsin in neuronal function and the impact of its deficiency.

See Also

• Ataxia
• Spasticity
• Peripheral Neuropathy
• Bouchard, J.P., Barbeau, A., Bouchard, R., & Bouchard, R.W. (1978). Autosomal recessive spastic ataxia of Charlevoix-Saguenay. *Canadian Journal of Neurological Sciences*, 5(1), 61-69.
• Vermeer, S., Meijer, R.P., Pijl, B.J., Timmermans, J., Cruysberg, J.R., Bos, M.M., Scheffer, H., & Kremer, H.P. (2008). ARSACS in the Netherlands: a frequent cause of early-onset cerebellar ataxia. *Neurogenetics*, 9(3), 207-214.

NIH genetic and rare disease info

• NIH info on Autosomal recessive spastic ataxia of Charlevoix-Saguenay

Autosomal recessive spastic ataxia of Charlevoix-Saguenay is a rare disease.