Spinocerebellar ataxia type 27B (SCA27B, MIM: 620174) is a recently established late-onset cerebellar ataxia associated with a pure GAA repeat expansion exceeding 250 repeat units in intron 1 of the fibroblast growth factor 14 gene (FGF14) [6–14]. The gene discussed is FGF14; the disease is cerebellar ataxia.