Abnormal sternum morphology (Human Phenotype Ontology identifier HP_0000766) is an anomaly of the sternum, also known as the breastbone. Also known as: Abnormality of the sternum, Pectus carinatum or pectus excavatum, Pectus deformities, Pectus deformity, Pectus excavatum or carinatum, Pectus excavatum or pectus carinatum, Pectus excavatum/carinatum, Sternal anomalies.