The Undiagnosed Diseases Program (UDP)?

Undiagnosed Diseases Programs exist for People Living With an Undiagnosed Disease (PLWUD) who are still searching for answers—often after years of tests, appointments, and uncertainty.

A UDP is not a first step in care. It is designed for individuals and families who have already gone far along their diagnostic journey and remain without a clear explanation.

The Golden Standard

At the Wilhelm Foundation, we believe that Undiagnosed Diseases Programs represent the gold standard in diagnostics for complex and unsolved conditions. UDPs combine deep clinical expertise, advanced technologies, and research-driven collaboration to give PLWUD the best possible chance of finding answers.

You may be eligible if you or your child

  • Are a child or adult with ongoing symptoms that doctors cannot yet explain
  • Have seen multiple specialists and undergone extensive medical investigations
  • Remain undiagnosed even after advanced genetic testing, such as whole-exome or whole-genome sequencing
  • Have symptoms that are complex, unusual, or do not fit known conditions
  • Have received different or uncertain diagnoses that do not fully explain the condition
  • Are part of a family where more than one person is affected, suggesting a possible genetic cause

People who are misdiagnosed are also considered undiagnosed. An incorrect diagnosis can delay appropriate care and prevent progress toward real answers.

How applications usually work

  • Many UDPs require a referral from a clinician, such as a pediatrician, neurologist, or clinical geneticist
  • Some programs allow families or adult patients to apply directly, often with medical records and clinician support
  • Applications typically include medical history, test results, and a clear summary of what remains unanswered

A global network: UDNI

Undiagnosed Diseases Programs are found all over the world and are connected through the Undiagnosed Diseases Network International (UDNI). UDNI is a global collaboration of UDPs working together across countries and healthcare systems. In the USA, they are connected through the UDN

What a UDP offers

Being accepted into a UDP does not guarantee a diagnosis. What it does guarantee is:

  • A thorough, multidisciplinary review of the case
  • Access to expertise and tools beyond routine healthcare
  • The opportunity to contribute to research that may help other PLWUD in the future

Today, around 40% of PLWUD can receive a diagnosis with existing tools. For the remaining 60%, UDPs, working together through UDN and UDNI to push science forward so that fewer families are left without answers.

At the Wilhelm Foundation, we stand with PLWUD and their families worldwide—advocating for access to UDP as the gold standard in diagnostics.