Direct mutation in the gene encoding the DUB occurs in Spinocerebellar ataxia type 3 (SCA3) due to CAG-trinucleotide expansion of the gene encoding ATXN3, resulting in polyglutamine expansion of the ATXN3 gene product, which is a deubiquitinase [47]. This evidence concerns the gene ZUP1 and Spinocerebellar ataxia type 3.