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Study Description

The Undiagnosed Diseases Network (UDN) is an initiative to facilitate the diagnosis of conditions that have eluded diagnosis through the coordinated action of leading clinical and research centers. The purpose of this cooperative research network is to establish a national network added to and building upon the NIH Undiagnosed Diseases Program (NIH UDP). The objectives of this program are to:

  1. Improve the level of diagnosis and care for patients with undiagnosed diseases through the development of common protocols designed by a community of investigators;
  2. Facilitate research into the etiology of undiagnosed diseases, by collecting and sharing standardized, high-quality clinical and laboratory data including genotyping, phenotyping, and documentation of environmental exposures; and
  3. Create an integrated and collaborative research community across multiple clinical sites and among laboratory and clinical investigators prepared to investigate the pathophysiology of these new and rare diseases and share this understanding to identify improved options for optimal patient management.

  • Study Types: Observational, Cross-Sectional, Parent-Offspring Trios
  • Number of study subjects that have individual level data available through Authorized Access: 462

Authorized Access
Publicly Available Data (Public ftp)

Connect to the public download site. The site contains release notes and manifests. If available, the site also contains data dictionaries, variable summaries, documents, and truncated analyses.

Study Inclusion/Exclusion Criteria
Inclusion criteria
  • The applicant has a condition that remains undiagnosed despite thorough evaluation by a healthcare provider and has at least one objective finding.
  • The applicant (or legal guardian) agrees to the storage and sharing of information and biomaterials in an identified fashion amongst the UDN centers, and in a de-identified fashion to research sites beyond the network.

Exclusion criteria
  • The applicant has a diagnosis that explains the objective findings.
  • Review of the records suggests a diagnosis and further evaluation is deemed unnecessary.
  • The UDN is unlikely to improve on the comprehensive workup the applicant already received.
  • The applicant is too seriously ill to travel safely to the UDN site and telemedicine/distance consult is not possible or appropriate.
Molecular Data
TypeSourcePlatformNumber of Oligos/SNPsSNP Batch IdComment
Exome capture Roche NimbleGen VCRome 2.1 (HGSC design) N/A N/A
Whole Exome Sequencing Illumina HiSeq 2500 N/A N/A
Whole Genome Sequencing Illumina HiSeq X N/A N/A
Study History

Without an explanation of 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). 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. The success of the NIH UDP prompted the NIH Common Fund to support the establishment of a network of medical research centers, called the "Undiagnosed Diseases Network" (UDN). The UDN clinical sites 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 gentic testing. In addition, the UDN furthers 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.

Selected publications
Diseases/Traits Related to Study (MESH terms)
Links to Related Resources
Authorized Data Access Requests
Study Attribution