Another channel gene implicated in SCA44 isGRM1, encoding the metabotropic glutamate receptor 1 (mGluR1) responsible for two phenotypic manifestations: adult-onset cerebellar ataxia in the presence of gain-of-function mutations and early onset ataxia with intellectual deficiency when associated with loss-of-function mutations72. Here, GRM1 is linked to cerebellar ataxia.