ATXN2 and spinocerebellar ataxia type 2: The long trinucleotide repeats expansions (≥36) in ATXN2 have been known to be related to spinocerebellar ataxia type 2 (SCA2) [108], but the intermediate length expansions (27–33 repeats) were also discovered to increase susceptibility to ALS [88], not only in FALS but also in SALS [109].