Available online 11 April 2024

SCA27B is one of the most frequent causes of late-onset cerebellar ataxia.

SCA27B is an autosomal dominant cerebellar ataxia linked to a (GAA) ≥ 250 repeat expansion in intron 1 of the FGF14 gene.

The pathogenicity of expansions (GAA)200–249 is still being evaluated, but in the presence of a compatible clinical phenotype, it may be considered.

The core phenotype consists of a slowly progressive late-onset cerebellar syndrome with frequent cerebellar-oculo-motor signs, such as, downbeat nystagmus, and episodic symptoms.

Genetic cerebellar ataxias are still a diagnostic challenge, and yet not all of them have been identified. Very recently, in early 2023, a new cause of late-onset cerebellar ataxia (LOCA) was identified, spinocerebellar ataxia 27B (SCA27B). This is an autosomal dominant ataxia due to a GAA expansion in intron 1 of the FGF14 gene. Thanks to the many studies carried out since its discovery, it is now possible to define the clinical phenotype, its particularities, and the progression of SCA27B. It has also been established that it is one of the most frequent causes of LOCA. The core phenotype of the disease consists of slowly progressive late-onset ataxia with cerebellar syndrome, oculomotor disorders including downbeat nystagmus, and episodic symptoms such as diplopia. Therapeutic approaches have been proposed, including acetazolamide, and 4-aminopyridine, the latter with a better benefit/tolerance profile.

Movement disorders

Gait disorders/ataxia

Spinocerebellar ataxia

Neurogenetics

SCA27B

© 2024 The Author(s). Published by Elsevier Masson SAS.