HTT and amyotrophic lateral sclerosis: Expansions of the CAG repeat in the ATXN2 gene, which cause spinocerebellar ataxia type 2, have been associated with increased risk of ALS (Sproviero et al., 2017), while patients carrying CAG triplet expansion in the Huntingtin (HTT) gene in a range between 27 and 35, referred to as an intermediate allele (IA), showed motor and cognitive changes (Cubo et al., 2016; Jot, 2019; Savitt and Jankovic, 2019).