Clinical and Genetic Evaluation of Individuals With Undiagnosed Disorders Through the Undiagnosed Diseases Network

Without an explanation for severe and sometimes life-threatening symptoms, patients and their families are left in a state of unknown. Many individuals find themselves being passed from physician to physician, undergoing countless and often repetitive tests in the hopes of finding answers and insight about what the future may hold. This long and arduous journey to find a diagnosis does not end for many patients- the Office of Rare Diseases Research (ORDR) notes that 6% of individuals seeking their assistance have an undiagnosed disorder. In 2008, the National Institutes of Health (NIH) Undiagnosed Diseases Program (UDP) was established with the goal of providing care and answers for these individuals with mysterious conditions who have long eluded diagnosis. The NIH UDP is a joint venture of the NIH ORDR, the National Human Genome Research Institute Intramural Research Program (NHGRI-IRP), and the NIH Clinical Research Center (CRC) (1-3). The goals of the NIH UDP are to: (1) provide answers for patients with undiagnosed diseases; (2) generate new knowledge about disease mechanisms; (3) assess the application of new approaches to phenotyping and the use of genomic technologies; and (4) identify potential therapeutic targets, if possible. To date, the UDP has evaluated 3300 medical records and admitted 750 individuals with rare and undiagnosed conditions to the NIH Clinical Center. The NIH UDP has identified more than 70 rare disease diagnoses and several new conditions. The success of the NIH UDP prompted the NIH Common Fund to support the establishment of a network of medical research centers, the Undiagnosed Diseases Network (UDN), for fiscal years 2013-2020. The clinical sites will perform extensive phenotyping, genetic analyses, and functional studies of potential disease-causing variants. The testing performed on patients involves medically indicated studies intended to help reach a diagnosis, as well as research investigations that include a skin biopsy, blood draws, and DNA analysis. In addition, the UDN will further the goals of the UDP by permitting the sharing of personally identifiable phenotypic and genotypic information within the network. By sharing participant information and encouraging collaboration, the UDN hopes to improve the understanding of rare conditions and advance the diagnostic process and care for individuals with undiagnosed diseases.

NCT Number	NCT02450851
Lead Sponsor	National Human Genome Research Institute (NHGRI)
Conditions	Genetic Disease
Enrollment	20,000 participants
Start Date	2015-09-16
Primary Completion	2028-12-31 (estimated)
Study Completion	2028-12-31 (estimated)
Updated on ClinicalTrials.gov	2026-07-28