An intronic GAA expansion in the FGF14 gene has recently been identified in several individuals with previously unexplained late-onset ataxia (PMID: 36516086, 36493768). The identification of this intronic expansion has led to the discovery of a new form of autosomal dominant hereditary ataxia, spinocerebellar ataxia type 27B (SCA27B). SCA27B is an autosomal dominant neurodegenerative disorder characterized by the onset of gait and appendicular ataxia in adulthood, usually around age 55 [MIM#620174]. About half of patients present with episodic features.