Spinocerebellar ataxia type 41 (SCA41) is a rare autosomal dominant cerebellar ataxia caused by mutations in the transient receptor potential canonical 3 (TRPC3) gene. We report a case of a patient with SCA41 whose clinical manifestations were initially suspected to be multiple system atrophy cerebellar-type (MSA-C). Whole-exome sequencing (WES) revealed a c.1955A>G (p.K652R) mutation in the TRPC3 gene of this patient. After treatment with transcranial magnetic stimulation and rehabilitation training, the patient reported a slight improvement in unsteady gait compared with before. This is the first report of SCA41 caused by the c.1955A>G variant in the TRPC3 gene, which expands the mutation spectrum of the TRPC3 gene. Clinicians should have sufficient awareness of SCA41, as SCA and MSA-C share overlapping clinical phenotypes and imaging features, which may easily lead to misdiagnosis, and genetic testing plays a crucial role in differentiating between the two disorders.
© 2026. The Author(s), under exclusive licence to The Japan Society of Human Genetics.