Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS): Case Report of a Novel Nonsense Mutation in the SACS Gene

摘要

Autosomalrecessivespasticataxia ofCharlevoix-Saguenay (ARSACS) isan autosomalrecessive neurodegenerative disordercharacterized by atriad ofearly onsetcerebellarataxia, spasticity,and sensorimotor polyneuropathy (distalmuscle wastingwith fingerand foot deformities).[1]Dysarthria, nystagmus,and retinal hypermyelinationmay sometimes be observed.[1] It was first described byBouchard et al. in1978 asanuncommon cause ofautosomalrecessivecerebellarataxia.[2,3] Although initially thought to be prevalent only inCanada, it has nowbeenincreasingly reported fromrest ofthe world.[4] Exomesequencing studies identified multiplecausative mutations in thesacsinmolecularchaperonegene(SACS) on chromosome 13q.[5] However, newpathogenic mutationscontinueto beidentified. Wereporta patient with typicalclinicalandimaging features ofARSACS, wheretargeted SACS genetesting lead to the discovery ofa novel pathogenic SACS mutation.