ATXN2 and autosomal dominant cerebellar ataxia: Finally, a CAG expansion analysis of more frequent SCA-related genes (ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, PPP2R2B, and TBP) allowed for the identification of a pathologic 58-triplet expansion in ATXN2 (Figure 1E, subject II-2, top line).