RFC1 and hereditary spastic paraplegia 7: In our large cohort of 3000 patients with ataxia, CANVAS due to RFC1 expansions was the third most common autosomal recessive (AR) ataxia after Friedreich’s ataxia (FA; 28%) and spastic paraplegia type 7 (SPG7) (14%), accounting for 11% of all AR ataxias.