Levodopa-Induced Ocular Dyskinesia in an Early-Onset Parkinson Disease Patient With GBA Mutation

OBJECTIVES: The aim of this study was to report a case of levodopa-induced ocular dyskinesia in an early-onset Parkinson disease patient and to investigate the pathogenic gene. METHODS: We report the case of a 49-year-old male patient with a 13-year history of Parkinson disease. Involuntary eye movements were noticed after treatment with amantadine for limb dyskinesias. Levodopa-induced ocular dyskinesias involving repetitive, transient, and stereotyped rightward deviations of gaze appeared after intake of an antiparkinsonian drug. Limb dyskinesias also occurred simultaneously. We used a next-generation sequencing targeted gene panel and found a heterozygous missense mutation (p.R535H) in GBA. Direct Sanger sequencing verified the missense mutation. CONCLUSIONS: We report the case of an uncommon early-onset PD patient carrying a GBA mutation presenting ocular dyskinesia. Genetic screening may provide a better mechanistic insight into dyskinesias.