Collectively these studies strengthen the hypothesis that dysregulation of mGluR signaling is a common, exacerbating factor in multiple forms of SCA (Meera et al., 2016; Power et al., 2016a), especially when considered in a larger context with monogenetic forms of ataxia which directly affect the mGluR1 and downstream genes (Yabe et al., 2003; van de Leemput et al., 2007; Guergueltcheva et al., 2012). This evidence concerns the gene GRM1 and Ataxia.