ATXN3 and Spinocerebellar ataxia type 3: Spinocerebellar ataxia type 3 (SCA3), also known as Machado–Joseph disease (MJD), is a neurodegenerative, late-onset, genetic disorder caused by the expansion of CAG repeats in the coding region of the ATXN3 gene (>50 in patients) (McLoughlin et al., 2020).