The GA4GH Rare Disease (RD) Community aims to promote global cooperation, data sharing, and collaborative rare disease research through identifying the need for new standards, and/or implementing existing GA4GH standards. This mission will be accomplished by collaboratively defining scientific rare disease use cases that may benefit from global cooperation, by a commitment to advancing those use cases through either the development or implementation of GA4GH standards, and by providing practical examples and guidance for rare disease sharing and analysis. The RD Community Connect session focuses on one of the most critical dimensions of RD diagnosis and care coordination: phenotypes. Deep phenotyping of patients suspected of or diagnosed with a RD — using the Human Phenotype Ontology — has become standard practice in the last ten years. And while the adoption of standardised terminologies and an increasing willingness to share data internationally have laid the foundation for progress in the RD field over the course of the last few years, for many patients the diagnostic odyssey will ultimately be futile: more than 50% of RD patients do not receive a molecular diagnosis.

This session aims to discuss some of the challenges underpinning further progress, including the encoding of longitudinal phenotypes, the communication and exchange of phenotypes in human language, or the definition and sharing of statistical data on phenotypes in diagnosed cohorts.