In the case of spinocerebellar ataxias (SCA), which are clinically and genetically heterogeneous, the mean age at onset of symptoms differs for SCA1, SCA2, SCA3, SCA6, SCA7, and could vary from third to fourth and even sixth decade of life (Warrenburg et al., 2005). This evidence concerns the gene ATXN3 and autosomal dominant cerebellar ataxia.