In mice, Sptbn2 targeting recapitulates adult-onset progressive ataxia, but expression of shorter SPTBN2 isoforms (Stankewich et al., 2010) or expression of alternative splice variants (Perkins et al., 2010) suggest that ataxia might reflect hypomorphism or neomorphism rather than complete loss of function. This evidence concerns the gene SPTBN2 and cerebellar ataxia.