Abnormal cerebellum morphology Cerebellar abnormalities UMLS:C0742038 HP:0001317 Abnormality of the cerebellum UMLS:C1866129 Cerebellar abnormality Cerebellar anomaly Cerebellar signs A malformed cerebellum may be abnormally small, dysplastic, or unusually large. The vermis and both hemispheres may be equally or disproportionately affected. Primary malformations of the pons, midbrain, and supratentorial structures are also seen in a substantial subset of patients. The wide range in morphological presentations results from the diversity of causes, including chromosomal abnormalities, specific genetic syndromes, and extrinsic factors. human_phenotype Any structural abnormality of the cerebellum. Abnormality of the metencephalon