Rare diseases comprise a clinically heterogeneous group of approximately 6,500 disorders each occurring in fewer than 200,000 persons in the USA. They are commonly diagnosed during childhood, frequently genetic in origin, and can have deleterious effects on long-term health and well-being. Although any given condition is rare, their cumulative public health burden is significant with an estimated 6-8% of individuals experiencing a rare disease at some point during their lives.

Because these disorders are so uncommon, no single institution, and in many cases no single country, has sufficient numbers of patients to conduct generalizable clinical and translational research. Geographic dispersion of patients has been a major impediment to patient recruitment into clinical trials. Most rare diseases do not have a specific International Classification of Diseases (ICD) code, which hampers research using existing administrative databases.

Best estimates are that fewer than 20% of rare diseases have registries, and most are operated by patients’ organizations or academic researchers. Although most registries are country-specific, there are a small number of international efforts—e.g., in Cystic Fibrosis and Neuromuscular Diseases— that are demonstrating the benefits of combining data across international boundaries.

Identifying patients and gathering genetic test results and clinical status parameters for many rare diseases is laborious and expensive. The Global Rare Diseases Patient Registry and Data Repository (GRDR) allows any rare disease population, regardless of size, to collect patient data that can identify clinical trial candidates and fuel research. By assembling many small patient registries into a common data repository, economies of scale can be realized and researchers will have the ability to look beyond a single gene/indication which may reveal non-obvious associations between genes and diseases.