Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS, Autosomal Recessive Spastic Ataxia Type 6) is an uncommon disorder with spasticity and ataxia usually starting in childhood.
Chromosome: 13q12.12
Gene affected: SACS (sacsin)
Inheritance: autosomal recessive
Clinical findings useful for diagnosis:
(1) slowly progressive cerebellar ataxia with difficulty walking and gait unsteadiness usually appearing during childhood
(2) spasticity of the lower limbs
(3) peripheral neuropathy with distal wasting and weakness
(4) thickened retinal hypermyelinated fibers (yellow streaks radiating from the edges of the optic disc on ophthalmic exam)
(5) vermis atrophy and/or atrophy of the cerebellar hemispheres on brain MRI
(6) hypointense bilateral stripes in the paramedian pons on brain MRI
Other findings include:
(1) hearing loss
(2) intellectual disability
(3) dysarthria
(4) urinary urgency and incontinence
(5) reduced life expectancy
