What is the Undiagnosed Diseases Network?

The Undiagnosed Diseases Network (UDN) is a research study that is funded by the National Institutes of Health Common Fund. Its purpose is to bring together clinical and research experts from across the United States to solve the most challenging medical mysteries using advanced technologies.

Through this study, we hope to both help individual patients and families living with the burden of undiagnosed diseases, and contribute to the understanding of how the human body works.

Who Is in the Network?

The UDN is made up of a Coordinating Center, Clinical Sites, and Core Facilities (“Cores”).

The Coordinating Center, which coordinates the work of the UDN, is based at the Department of Biomedical Informatics at Harvard Medical School.

The Clinical Sites, where UDN participants are evaluated, are located in 12 cities across the United States:


At the Clinical Sites, doctors and healthcare providers, like neurologists, immunologists, nephrologists, endocrinologists, and geneticists, come together to help find the cause of participant symptoms.

The Sequencing Core, where genetic testing for the UDN is performed, is at Baylor College of Medicine.

The Model Organisms Screening Center, located at Baylor College of Medicine, Washington University in St. Louis, and University of Oregon, helps the network to understand how specific genetic changes contribute to disease by studying these changes in other organisms. The Metabolomics Core, located at the Mayo Clinic in Rochester, MN, provides the UDN with advanced tools to study biological markers that might be related to disease.

How Can I Apply to be a UDN Participant?

You can visit our How to Apply page to learn more and begin the UDN application process.