FGF14 and cerebellar ataxia: Spinocerebellar ataxia 27B (SCA27B) (MIM: 620174) is a dominantly inherited neurodegenerative disease caused by (GAA)•(TTC) trinucleotide repeat expansion in the first intron of isoform 1b of the fibroblast growth factor 14 (FGF14) gene.1,2 This pathogenic repeat expansion has emerged as one of the most common causes of late-onset cerebellar ataxia (LOCA).1,3 The primary clinical characteristics of SCA27B encompass slowly progressive cerebellar ataxia, episodic symptoms, ocular motor signs, such as downbeat nystagmus and visual disturbances.1,2,4,5