350 million people live with an undiagnosed disease

Undiagnosed Day

On April 29 we mark Undiagnosed Day—this isn't just a day, it's a movement. It's not about the disease; it's about raising awareness and taking action for people living with undiagnosed diseases (PLWUD). Too many people are living with unanswered questions.

This day is dedicated to the 350 million People Living With Undiagnosed Diseases (PLWUD) and their families but also for the clinicians, researchers, genetic counsellors and patient organizations working tirelessly to find answers.

Undiagnosed Day 2026 in Gdańsk — A Successful Collaboration with ERDERA, the Medical University of Gdańsk, and the University Clinical Centre in Gdańsk

On April 29–30, 2026, Undiagnosed Day was marked in Gdańsk, Poland through a powerful two-day international meeting focused on improving diagnosis for children and adults living with undiagnosed conditions.

The event was organized by Wilhelm Foundation in collaboration with ERDERA, the Medical University of Gdańsk, and the University Clinical Centre in Gdańsk. Together, we brought clinicians, clinical geneticists, researchers, invited experts, stakeholders and families with undiagnosed diseases together around one shared mission: to move diagnosis forward when the answer is not obvious.

Wilhelm Foundation is especially happy to continue the successful Phenotyping Roundtable model that was first carried out during Undiagnosed Day 2025 in Singapore. The experience in Singapore showed the power of bringing families, clinicians, and experts together in one focused setting — where careful clinical observation, shared reasoning, and collaboration can open new diagnostic directions.

In Gdańsk, the first day was a closed Phenotyping Roundtable, where children and families living with undiagnosed diseases met directly with specialists. The families were from Poland and the neighbouring countries. Through careful clinical observation, multidisciplinary discussion, and shared clinical reasoning, each case was reviewed with the goal of identifying new diagnostic directions and practical next steps.

On the second day, the conversation was opened up to a wider audience through an international conference on modern diagnostics, data sharing, interdisciplinary collaboration, family involvement and the challenges that remain when no diagnosis is found.

Gdańsk showed what Undiagnosed Day is truly about: making the invisible visible, bringing families out of isolation, and proving that diagnosis is not only a scientific challenge — it is also a human one.

This successful collaboration with ERDERA and the Medical University of Gdańsk strengthened Undiagnosed Day as a global platform for awareness, solidarity, and action for People Living With Undiagnosed Diseases (PLWUD).

Thank you ERDERA, the Medical University of Gdańsk, and the University Clinical Centre in Gdańsk and all the collaborators and families!

Undiagnosed diseases are not rare — they are unseen.

Together, we can shorten the diagnostic odyssey.

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