These non‐coding repeat expansions, which respectively cause the cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS, MIM 614575) and spinocerebellar ataxia (SCA) 27B (SCA27B/GAA‐FGF14 ataxia, MIM 620174), account for a substantial share of previously undiagnosed cases of sporadic and familial late‐onset ataxia. This evidence concerns the gene FGF14 and aceruloplasminemia.