Aplasia/Hypoplasia of the cerebellum

• Absent/small cerebellum
• Absent/underdeveloped cerebellum
• Atrophy/Degeneration affecting the cerebellum
• Atrophy/Hypoplasia of the cerebellum
• Cerebellar hypoplasia/atrophy

• has_part some (
      aplastic/hypoplastic and
      inheres in some cerebellum and
      has modifier some abnormal)

• Abnormal cerebellum morphology
• Aplasia/Hypoplasia involving the central nervous system