Autosomal recessive spastic ataxia of Charlevoix-Saguenay in a Portuguese child caused by a novel SACS mutation

Abstract

Introduction: Autosomal recessive spastic ataxia of Charlevoix–Saguenay (ARSACS) is a rare neurodegenerative disease characterized by cerebellar ataxia, peripheral neuropathy and pyramidal tract signs. Since its first report from Québec, more than 100 disease-causing variants have been reported in ARSACS, with variable clinical presentation. MRI imaging may help establishing the clinical diagnosis, especially if typical changes are present. Clinical case: A 7-year old boy presented an early-onset, progressive ataxia, with sensory-motor neuropathy, nystagmus, feet deformities and cognitive impairment. MRI findings showed cerebellar and cervical spine atrophy and linear areas of hypointensity in the pons. The finding of a novel homozygous mutation -c.3066del(p. Asn1025Metfs*10) -in the SACS gene, resulting in a frameshift and a premature stop codon, allowed the genetic confirmation of the clinical diagnosis.