• David Pellerin, Carlo Wilke, Andreas Traschütz, Sara Nagy, Riccardo Currò, Marie-Josée Dicaire, Hector Garcia-Moreno, Mathieu Anheim, Thomas Wirth, Jennifer Faber, Dagmar Timmann, Christel Depienne, Dan Rujescu, José Gazulla, Mary M Reilly, Paola Giunti, Bernard Brais, Henry Houlden, Ludger Schöls, Michael Strupp, Andrea Cortese, and Matthis Synofzik.
• Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, University College London, London, UK matthis.synofzik@uni-tuebingen.de david.pellerin.21@ucl.ac.uk.
• J. Neurol. Neurosurg. Psychiatr. 2024 Jan 11; 95 (2): 175179175-179.

BackgroundIntronic GAA repeat expansions in the fibroblast growth factor 14 gene (FGF14) have recently been identified as a common cause of ataxia with potential phenotypic overlap with RFC1-related cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS). Our objective was to report on the frequency of intronic FGF14 GAA repeat expansions in patients with an unexplained CANVAS-like phenotype.MethodsWe recruited 45 patients negative for biallelic RFC1 repeat expansions with a combination of cerebellar ataxia plus peripheral neuropathy and/or bilateral vestibulopathy (BVP), and genotyped the FGF14 repeat locus. Phenotypic features of GAA-FGF14-positive versus GAA-FGF14-negative patients were compared.ResultsFrequency of FGF14 GAA repeat expansions was 38% (17/45) in the entire cohort, 38% (5/13) in the subgroup with cerebellar ataxia plus polyneuropathy, 43% (9/21) in the subgroup with cerebellar ataxia plus BVP and 27% (3/11) in patients with all three features. BVP was observed in 75% (12/16) of GAA-FGF14-positive patients. Polyneuropathy was at most mild and of mixed sensorimotor type in six of eight GAA-FGF14-positive patients. Family history of ataxia (59% vs 15%; p=0.007) was significantly more frequent and permanent cerebellar dysarthria (12% vs 54%; p=0.009) significantly less frequent in GAA-FGF14-positive than in GAA-FGF14-negative patients. Age at onset was inversely correlated to the size of the repeat expansion (Pearson's r, -0.67; R2=0.45; p=0.0031).ConclusionsGAA-FGF14-related disease is a common cause of cerebellar ataxia with polyneuropathy and/or BVP, and should be included in the differential diagnosis of RFC1 CANVAS and disease spectrum.© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.

17 keywords...

hide…