Aplasia or Hypoplasia affecting the metacarpal bones. The phenotype is Human Phenotype Ontology term HP_0005914 (Aplasia/Hypoplasia involving the metacarpal bones). Also known as: Absent or hypoplastic metacarpals, Absent/small long bones of hand, Absent/underdeveloped long bones of hand, Aplastic/hypoplastic metacarpals, Hypoplastic metacarpals, Hypoplastic/absent metacarpal bones, Hypoplastic/absent metacarpals, Metacarpal aplasia/hypoplasia.