Machado-Joseph disease (MJD) or Spinocerebellar ataxia type 3 (SCA3) is a dominant fatal inherited disorder of the central nervous system (CNS) caused by overrepetition of the CAG trinucleotide in the coding region of the MJD1/ATXN3 gene, which encodes the ataxin-3 protein (Atx3) [1]. This evidence concerns the gene ATXN3 and Machado-Joseph disease.