Ataxia, spastic, Charlevoix-Saguenay type

[MIM 270 550]

(ARSACS acronym Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay).

Cause of at least 5 % of the early-onset spinocerebellar ataxia cases. It could be the second cause of congenital ataxia after Friedreich's disease. Most common in the region of Charlevoix-Saguenay in Canada (incidence estimated at 1/1,932).

Autosomal recessive transmission of a mutation of the SACS gene on 13q 11. This gene codes for a large protein called sacsin, that could mediate the three-dimensional conformation of other proteins.


Neurodegenerative disease that combines to varying degrees:

-         cerebellar ataxia: early-onset in the Quebec form (around 12-18 months), later-onset in other countries; difficulties for walking, dysarthria, nystagmus

-          progressive spasticity (less severe in Japanese patients) 

-         pyramidal syndrome

-         peripheral neuropathy: onset is later and results in a distal amyotrophy, abolition of some reflexes, deep sensitivity disorders. EMG: decrease in motor and sensory conduction speeds

-         MRI: early-onset atrophy of the upper part of the cerebellar vermis and the cerebellar hemispheres (sometimes also of the parietal cortex), and finally the cervical spine; often arachnoid cyst in the posterior fossa

-  ophthalmoscopy (in Quebec form): hypermyelination of the optic nerve fibers that spread out of the optical  disc and accompany the retinal vessels

Also:

-         mitral valve prolapse 

-         pes cavus

-         bladder dysfunction: unstable bladder

-         epilepsy: 7 %

Treatment: physiotherapy, occupational therapy, psychological support.


Anesthetic implications: 

preoperative cardiac ultrasound (mitral valve prolapse?); difficulties to monitor curarization


References : 

-        Martin M-H, Bouchard J-P, Sylvai M, St Onge O, Truchon S. 
Autosomal recessive spastic ataxia of Charlevoix-Saguenay: a report of MR imaging in 5 patients. 
AJNR 2007; 28: 1606-8.

-         Synofzik M, Soehn AS, Gburek-Augustat J et al. 
Autosomal recessive spastic ataxia of Charlevoix Saguenay (ARSACS) : expanding the genetic, clinical and imaging spectrum. 
Orphanet J Rare Diseases 2013; 8:41


Updated: November 2019