Human Phenotype Ontology identifier HP_0001272 (Cerebellar atrophy) is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Also known as: Atrophic cerebellum, Degeneration of cerebellum.