DRPLA has additional similarities with SCA3/MJD: the gap between the normal range and the pathogenic range of CAGn is large (Figure 1); CAGexp on ATN1 is favorably segregated (Ikeuchi et al., 1996); there appear to be very few ancestral haplotypes (Martins et al., 2003); and the existence of neurological subtypes, where manifestations are qualitative different, depending on AO. Here, ATN1 is linked to Machado-Joseph disease.