Among the 140 patients diagnosed with cerebellar ataxia, 74 patients were diagnosed as SCA, including SCA1 (n=1), SCA2(n=6), SCA3(n=64), SCA6 (n=1) and SCA17 (n=2), while 66 patients were diagnosed as clinically possible or probable MSA-C. This evidence concerns the gene ATXN2 and autosomal dominant cerebellar ataxia.