Analysis of Causal Relationships in Integrated Ontologies of Diseases, Phenotypes, and Radiological Diagnosis.

Biomedical ontologies encode knowledge in a form that makes it computable. The current study used the integration of three large biomedical ontologies-the Disease Ontology (DO), Human Phenotype Ontology (HPO), and Radiology Gamuts Ontology (RGO)-to explore inferred causal relationships between high-level DO and HPO concepts. The principal DO categories were defined as the 7 direct subclasses of the top-level Disease class, excluding Disease of anatomical entity, plus the 12 direct subclasses of the latter term. The principal HPO categories were defined as the 25 direct subclasses of HPO's Phenotypic abnormality class. All causal relationships were tallied between members of the DO and HPO principal categories through their causal relationships in RGO. The analysis provides an understanding of the hierarchical organization of RGO terms, and offers insights into new relationships between DO and HPO classes.