polyQ expansion of ATXN2 has also recently been linked to the age-at-onset of a neurodegenerative disease closely related to ALS/SCA2, known as spinocerebellar ataxia type III (SCA3) or Machado-Joseph’s disease (MJD) [112,113,114]. Here, ATXN2 is linked to spinocerebellar ataxia type 2.