RT Journal Article SR Electronic T1 Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS): genetic and clinical aspects JF Practical Neurology JO Pract Neurol FD BMJ Publishing Group Ltd SP 14 OP 18 DO 10.1136/practneurol-2020-002822 VO 22 IS 1 A1 Andrea Cortese A1 Riccardo Curro' A1 Elisa Vegezzi A1 Wai Yan Yau A1 Henry Houlden A1 Mary M Reilly YR 2022 UL http://pn.bmj.com/content/22/1/14.abstract AB Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) typically presents in middle life with a combination of neuropathy, ataxia and vestibular disease, with patients reporting progressive imbalance, oscillopsia, sensory disturbance and a dry cough. Examination identifies a sensory neuropathy or neuronopathy and bilaterally impaired vestibulo-ocular reflex. The underlying genetic basis is of biallelic AAGGG expansions in the second intron of replication factor complex subunit 1 (RFC1). The frequency and phenotype spectrum of RFC1 disease is expanding, ranging from typical CANVAS to site-restricted variants affecting the sensory nerves, cerebellum and/or the vestibular system. Given the wide phenotype spectrum of RFC1, the differential diagnosis is broad. RFC1 disease due to biallelic AAGGG expansions is probably the most common cause of recessive ataxia. The key to suspecting the disease (and prompt genetic testing) is a thorough clinical examination assessing the three affected systems and noting the presence of chronic cough.