ATXN3 and Kennedy disease: Today, nine heritable polyglutamine misfolding diseases are known, namely Huntington’s chorea, spinal and bulbar muscular atrophy (SBMA) or Kennedy’s disease, spinocerebellar muscular atrophy 1 (SCA1), SCA2, SCA3 or Machado-Joseph disease, SCA6, SCA7, SCA12, SCA17 and dentatorubral-pallidoluysian atrophy (DRPLA) or Haw River syndrome [19,20,21,22,23,24,25,26,27,28,29].