The proband of 12 ARCA families and 37 sporadic SCA patients, previously excluded for the FRDA, SCA1, SCA2, SCA3, SCA6, SCA7, SCA8, SCA10, SCA12, SCA17 and DRPLA mutations, were analysed for this novel SETX mutation. Here, ATXN3 is linked to autosomal dominant cerebellar ataxia.