Association of RFC1-repeat expansion and late-onset ataxia


  • Replication factor complex subunit 1 (RFC1)-disease is frequent, with cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) and ataxia-with-chronic-cough (ACC) as highly diagnostic phenotypes.

Why this matters

  • Biallelic, intronic AAGGG repeat expansions in RFC1 have recently been identified as a frequent cause of late-onset ataxia, especially in CANVAS.

  • RFC1 repeat-expansions have an estimated allele frequency of 0.7–4.0%, suggesting that there is a significant number of unidentified RFC1-patients and highlights a need to prepare the first translational steps towards trial-readiness for this novel disease.

  • This study revealed the frequency of RFC1-disease amongst patients with late-onset ataxia as well as the rate of ataxia progression in these patients. This information provided a sample size estimate for future trials in which treatment efficacy for ataxia can be established.