SCA27B is an autosomal dominant disorder caused by a GAA repeat expansion in intron 1 of the fibroblast growth factor 14 (FGF14) gene, that has recently been recognized (2023) as one of the most common genetic forms of late-onset ataxia (Wilke et al. 2023; Clément et al. 2024; Pellerin et al. 2024b). The gene discussed is FGF14; the disease is late-onset spinocerebellar ataxia 27b.