Long-term response to aminopyridines in a cohort of patients with ataxia associated with downbeat nystagmus due to the FGF14 GAA expansion

FGF14 (intronic GAA expansion, SCA27B)

FGF14 intronic GAA expansion (>250 repeats) → Nav1.6 sodium channel dysfunction → impaired Purkinje cell excitability; aminopyridines block potassium channels and partially restore cerebellar function

Multicenter Spanish cohort of patients with downbeat nystagmus ataxia (A-DBN) due to the FGF14 intronic GAA expansion (SCA27B). The study documents clinical, radiological and genetic features, and long-term response to aminopyridines (4-aminopyridine or 3,4-diaminopyridine). The sustained clinical response to aminopyridines in the majority of patients reinforces the therapeutic indication in this recently identified form of ataxia.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

SCA27B is one of the most common adult cerebellar ataxias in recent cohorts (up to 20% of cryptogenic A-DBN). FGF14 genotyping should be systematic in any patient with late-onset A-DBN. The aminopyridine response provides an additional argument for early testing (accessible and effective treatment).

genetic expansion + longitudinal therapeutic data +2; multicenter Spanish cohort +2; long-term aminopyridine response documented +2; Neurologia +1