RFC1 and cerebellar ataxia: Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) is an autosomal recessive adult-onset, slowly progressive neurologic disorder caused by biallelic expanded 5-bp intronic repeats in the RFC1. After the AAGGG was identified as a causative repeat motif [1], the ACAGG motif expansion was found in the Asia–Pacific [2] and Japanese [3, 4] CANVAS cohorts, and it was supposed to be pathogenic.