The biallelic AAGGG intronic repeat expansion in RFC1 associated with CANVAS and the deep intronic GAA repeat expansion in FGF14 associated with SCA27B are absent from most commercial repeat expansion panels for ataxia, despite emerging evidence demonstrating their prevalence as some of the more common causes of undiagnosed cerebellar ataxia [86,87] and late-onset cerebellar ataxia [35,88]. Here, RFC1 is linked to cerebellar ataxia.