RFC1 and cerebellar ataxia: European population cohort studies have demonstrated that pathogenic RFC1 expansions underlie a substantial proportion of clinically suspected CANVAS as well as ataxia and neuropathy cases.4,13‐15 It has been postulated that the disease shows spatial progression initially involving sensory neurons, with cerebellar and vestibular dysfunction manifesting later.13 Thus, RFC1 should still be considered in cases not presenting with all three features characteristic of the disease.