Establishing Patient Registries for Rare Diseases: Rationale and Challenges.

Globally, an estimated 350 million people are affected by a rare disease diagnosis. Knowledge limitations persist for the majority of rare conditions due to systemic and structural challenges in healthcare and research. Disease-specific patient populations are often small and geographically dispersed; funding support for research is restricted; and diagnostic delays are common due to disease complexities, limited medical training for practitioners, and evolving foundational knowledge related to disease characterization.