A novel mutation in the SACS gene associated with a complicated form of spastic ataxia.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay type (ARSACS; MIM 270550) is characterized by early-onset progressive spastic ataxia, mild cognitive impairment, axonal polyneuropathy, predominant vermian atrophy at brain MRI, and characteristic hypermyelinated retinal nerve fibers at fundoscopy [1, 2]. Mutations in SACS, on chromosome 13q11 were first identified in French-Canadian patients [3]; subsequently extension of molecular screening to larger cohorts of patients led to the identification of ARSACS worldwide and also to broaden both its genotypic and its phenotypic spectrum [