PPP2R2B and autosomal dominant cerebellar ataxia: 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.