The identification of biallelic (AAGGG)nRFC1 expansions in our adult-onset ataxia cohort clearly indicates the need to screen adult-onset ataxia patients for expanded RFC1 repeats when no other genetic cause is found in other known ataxia genes, and particularly when adult-onset ataxia is combined with sensory neuropathy. The gene discussed is RFC1; the disease is Sensory neuropathy.