Wilhelm Foundation is a global non-profit with a bold mission: to end the diagnostic odyssey and bring answers to all People Living With Undiagnosed Diseases (PLWUD). Representing an estimated 350 million individuals worldwide, they unite experts, technology, and families through initiatives such as the Undiagnosed Hackathon and Global Undiagnosed Day (April 29th)—making the invisible visible and pioneering new ways to uncover diseases the medical field cannot yet explain.
April 2026
Helene Cederroth
Founder and CEO, Wilhelm Foundation
S. Christy Rohani-Montez: I’m so pleased to be speaking today with Helene Cederroth, co-founder, along with her husband Mikk, of the Wilhelm Foundation. So welcome Helene, and could I please ask you to introduce yourself and explain the origins of the Wilhelm Foundation?
Helene Cederroth: Yes, I am Helene Cederroth, a mother of 4 children. My 3 youngest children suffered from an undiagnosed, severe disease that we were initially told was manageable. It was devastating when our son Wilhelm, at 12, developed dementia, and we realized the severity of the condition. In the end we lost all 3 of our youngest children in 3 years (1999–2002).
We founded the Wilhelm Foundation at Wilhelm’s funeral in 1999 because we wanted to help other families avoid the same devastating situation. We started by organizing the Undiagnosed Diseases Network International (UDNI) along with Dr William A. Gahl (NIH, USA) and Dr Domenica Taruscio (ISS, Italy); and so far, have held 14 UDNI conferences for specialists to foster collaboration. But since 60% of patients remain undiagnosed, we needed a more direct solution, which led to the Hackathon.
S. Christy Rohani-Montez: And so, what is the Wilhelm Foundation’s Undiagnosed Hackathon initiative, and how is it structured to solve cases that traditional methods have missed?
Helene Cederroth: The mission is to find new ways and new collaborations to solve those >60% of undiagnosed cases. We invite a number of families with undiagnosed conditions to attend. The main criteria for families to participate is that they must have already undergone negative whole-genome or whole-exome sequencing. And we invite a variety of experts, including clinicians, geneticists, bioinformaticians, and AI specialists—who normally don’t work together—and divide them into interdisciplinary groups from different countries and backgrounds.
Crucially, we don't put titles on name tags, so everyone is equal and encouraged to collaborate, overcoming the typical issues that prevent sharing information. The presence of the families allows participants to look at the phenotype, symptoms, and dysmorphic features first hand—so they see real people, not just files and data.
And this makes a big difference. You can feel something special in the air at the Hackathon with everyone working so intensively. And when they come to a diagnosis, they ring a bell. It’s wonderful to hear the bell ring.
S. Christy Rohani-Montez: What kind of success rate have you seen, and is there a memorable case that demonstrates the power of this collaborative approach?
Helene Cederroth: We diagnose about 40% of the cases presented. These are families who have already completed every known diagnostic step, often through Undiagnosed Disease Programs (UDP). For instance, at one Hackathon, we reviewed the case of a child from Turkey with a horrible disease, causing blisters and scars on her hands and feet, preventing her from walking. When collaborators came together, one suggested a disease typically found only in Brazil and Portugal. Despite the family having no known connection to those countries, that was in fact the diagnosis, and we have now published the case.
S. Christy Rohani-Montez: Many physicians feel a diagnosis is unnecessary if there is no treatment. But what does it mean for families to have a diagnosis regardless?
Helene Cederroth: Receiving a diagnosis, even a severe or life-threatening one, is immensely important; it means a new perspective. First, it clarifies if the condition is hereditary, which is vital for family planning. Second, a diagnosis can help identify which medications may be harmful and should be avoided; and third, families can search for others with the same disease, establish organizations, and explore treatment options, including drug repurposing. Most critically, it alleviates the psychological burden, especially for mothers who think they did something wrong during the pregnancy, which is very common. It also removes the horrible stigma and suspicion from some healthcare providers who, if a diagnosis cannot be found, unfairly suggest the mother is causing harm.
S. Christy Rohani-Montez: Given that 60% of families are still undiagnosed, what are you most excited about in the future for making diagnoses easier and earlier?
Helene Cederroth: I am excited about advancements in technology like long-read sequencing, RNA sequencing, and proteomics, and I think they will solve many more undiagnosed cases. I also think AI can help raise the standards for diagnosis and address the difficulties in obtaining sequencing for low- and middle-income countries.
This is so important because when you think about it, the average diagnostic delay of 4 to 6 years that we hear so often is only true for the 40% of cases where the disease is actually diagnosed; the remaining 60% can wait a lifetime. It has taken 25 years to build this movement, but now suddenly, everything is coming together, and it is amazing.
S. Christy Rohani-Montez: The work you are doing is absolutely amazing. Thank you for speaking with me Helene!
To learn more about the Wilhelm Foundation, visit https://wilhelmfoundation.org/ and the Undiagnosed Hackathon: https://undiagnosedhackathon.org/