Reliable fluid biomarkers and disease modifying therapies are waited for spinocerebellar ataxias (SCAs). SCA31 is characterized by a late-onset slowly progressive cerebellar ataxia, caused by a penta-nucleotide expansion containing (TGGAA)_n in an intron of BEAN1 (Am J Hum Genet 2009; 85: 544-57). As clinical trials against SCAs using molecular therapies are expected in future, it became essential for us to understand progression rates as well as biomarkers in SCA31. Previous studies reported that an annual progression rate of SCA31 in the Scale for the Assessment and Rating of Ataxia (SARA) score was 0.8 ± 0.1 points (Cerebellum 2017; 16: 518-24). However, detailed clinical parameters are needed to address efficacies of therapies.

So far, 13 participants completed first year observations. Despite that our program is more comprehensive than other programs such as Ataxia Functional Composite Scale (Mov Disord 2021;36(2):283-297), no significant concerns were encountered.  By April, 2024, thirty patients are expected to be enrolled for the first year study.

Our detailed clinical testing program appears generally applicable for clinical assessment and searching biomarkers in cerebellar ataxias.