[Initiative on Rare and Undiagnosed Diseases: Achievements and Future Prospects]

The Initiative on Rare and Undiagnosed Diseases (IRUD) was a project for patients who remain undiagnosed after undergoing various clinical tests. This project includes both the clinical aspect of diagnosing rare diseases and the research aspect of identifying new diseases. Since 2015, the diagnosis rate for undiagnosed patients has been 40-50%. From a clinical perspective, this project demonstrated how genome analysis has become indispensable in rare diseases, especially in pediatrics. From a research standpoint, over 30 diseases have been identified through this project. This project was coordinated with a similar undiagnosed disease program from outside the country, and we strongly believe that much success has been achieved. Future challenges include examining which approaches (e.g., long-read genome analysis, transcriptome analysis, and methylation analysis) would be effective for undiagnosed patients after exome analysis, and developing therapeutic drugs for rare diseases. Future challenges include addressing the approximately 50% of patients whose undiagnosed diseases cannot be diagnosed even after exome analysis and developing therapeutic agents for the rare diseases that have been diagnosed.