The Human Phenotype Ontology (HPO) contains more than 10,000 terms and provides a structured and controlled vocabulary for the phenotypic features encountered in human hereditary and other diseases. The HPO itself does not describe individual disease entities but, rather, the phenotypic abnormalities associated with them. It is currently being developed using information from OMIM mainly, as well as from other medical information sources such as ORPHANET or DECIPHER. The combination of HPO together with the ORPHANET disease classification represents a promising resource for automated rare disease classification.
Several tools have been developed to be used by clinicians in order to optimize the exploitation of the HPO. Phenotips, PhenomeCentral, and Phenomizer are some tools currently available. All of them focus on providing assistance in diagnosis, but they offer different possibilities:
• Phenotips: It is an open source software tool for collecting and analyzing phenotypic information for patients with genetic disorders. The local software is useful for clinicians or a closely related group who are managing a unique database.
• PhenomeCentral: It is a centralized repository for secure data sharing targeted to clinicians and scientists working in the rare diseases community. This software offers an interesting possibility of sharing complex phenotypes with other researchers worldwide. The system allows researchers to initiate contacts among them by email.
• Phenomizer: It is a website resource which does not make a diagnosis, rather it produces a ranked (by probabilities) list of possibilities that can be used by physicians as a part of the diagnostic workup.