That interrupted and uninterrupted polyQ repeat expansions with similar length in ATXN2 lead to different neurological presentations (SCA2 or parkinsonism) highlights the possibility that repeat sequence configuration, as well as repeat length, is an important arbiter in clinical manifestation and phenotypic variability in ATXN2-associated pathologies. This evidence concerns the gene ATXN2 and spinocerebellar ataxia type 2.