Expanding the Clinical Spectrum of ARSACS: An Atypical Adolescent-Onset Presentation with Compound Heterozygous SACS Variants

Abstract

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare hereditary neurodegenerative disorder caused by biallelic pathogenic variants in SACS.Initially described in the French-Canadian population, ARSACS is now recognized worldwide and ranks among the most common forms of autosomal recessive cerebellar ataxia. 1 The classical phenotype comprises cerebellar ataxia, lower-limb spasticity, and peripheral neuropathy.However, increasing clinical evidence has revealed substantial phenotypic heterogeneity, including atypical and late-onset presentations that may lack one or more components of this classical triad. 2 Consequently, diagnosis can be challenging, particularly when incomplete phenotypes