The p.Arg4378X variant has been already reported in trans with another pathogenic variant in the SACS gene (c.1178_1181delAT; p.Leu393Cysfs*17) in a patient with ARSACS.14 We further validated the pathogenicity of this variant by assaying vimentin remodelling by immunofluorescence in primary fibroblasts from PN7 and comparing to PN6 and healthy controls. Here, VIM is linked to Charlevoix-Saguenay spastic ataxia.