Spinocerebellar ataxia type 31 (SCA31) is a very rare subtype of autosomal dominant cerebellar ataxia type III (ADCA type III) characterized by the late-onset of cerebral ataxia, dysarthria and horizontal gaze nystagmus, and that is occasionally accompanied by pyramidal signs, tremor, decreased vibration sense and hearing difficulties. The disease is spinocerebellar ataxia type 31 (Monarch Disease Ontology id MONDO_0007296). Also known as: SCA31.