A rare hereditary ataxia characterized by adult onset of slowly progressive cerebellar degeneration with gait ataxia, dysmetria, dysarthria, and in some cases diplopia. Cognitive functions are normal, and seizures are absent. Magnetic resonance imaging reveals mild atrophy of the cerebellar vermis. The disease is Monarch Disease Ontology id MONDO_0033482 (spinocerebellar ataxia 47). Also known as: PUM1-related cerebellar ataxia.