November 26, 2025
In early June 2023, more than a hundred scientists from across the globe convened in Stockholm, Sweden. They packed into the halls and auditoriums of the medical building of Karolinska Institute for the first Undiagnosed Hackathon, a meeting with the goal of finding new ways to solve undiagnosed diseases.
The third annual three-day event took place at the end of September. A total of 122 scientists, geneticists, bioinformaticians, clinicians, and AI experts from 28 countries across six continents traveled to the Mayo Clinic in Rochester, Minnesota, for the first US-based Undiagnosed Hackathon.
More than 350 million people worldwide live with medical conditions that have not received a true, causative diagnosis—a single diagnosis that can explain a range of symptoms—despite extensive evaluation. Children are disproportionately affected, as they constitute roughly half of the cases. Now, advances in genome sequencing are enabling clinicians to solve about 40% of such cases. “That’s amazing,” says Helene Cederroth, a mother and founder of the Wilhelm Foundation. “But we have to talk about the 60% we can’t solve.”
For Cederroth, helping solve medical mysteries for families is personal because she is acutely familiar with the pain and tragedy of living with and caring for children with undiagnosed medical conditions. Three of her four children died without a causative diagnosis. She founded the Wilhelm Foundation in 1999, named after her son who died at 16.
The Wilhelm Foundation has since pioneered several innovative initiatives that focus on bringing visibility to people living with undiagnosed diseases (PLWUD). This makes the Wilhelm Foundation unique, as patient organizations are typically formed around a single diagnosis. The global Undiagnosed Hackathon is potentially the Foundation’s most groundbreaking initiative.
At the 2025 hackathon, expert teams worked to understand the symptoms and experiences of 29 individuals. The local individuals and their families got to share their stories and answer questions that their diagnostic team had for them.
The experts utilized a powerful suite of technologies, including short-read and long-read DNA sequencing, RNA sequencing, methylation, variant interpretation software, and diverse phenotypic and AI tools. Some 48 hours later, the teams found six answers, with a further nine having significant leads.
Illumina contributed in-kind donations and flew three employees, Aditi Chawla, a clinical genomics scientist, Richard Wang, a bioinformatics scientist, and Shirlene Badger, global patient advocacy lead, to the hackathon to sit on the tech team. “At Illumina, we know that our technologies are not only providing a diagnosis, they are changing lives,” Badger says. “Diagnosis can be information. It can be navigation. It can be community and it can be access. It is care—the ability to both cry out and challenge stigma and create new possibilities.”
Illumina also helped support the Wilhelm Foundation in bringing researchers from low- and middle-income countries to the event.
“Undiagnosed people are left behind worldwide, but it’s very severe in the low- and middle-income countries,” says Cederroth, who attributes this to lack of access, awareness, and scientific resources. “So it’s important that they could come and work together.”
Attracting PLWUD and medical experts from these countries is important to Cederroth because the Wilhelm Foundation collaborates with the Undiagnosed Diseases Network International (UDNI) on the Champion Initiative. Specialists within the network can share new techniques, abnormalities, or methods of diagnosis with one another so PLWUD in relatively underresourced places can still get the expertise they need to manage their condition.
Moving forward, Cederroth is looking to help build a diagnosis pipeline for the Undiagnosed Hackathon that allows individuals to manage their own access to sequencing and bring the data to geneticists elsewhere for further evaluation.
Cederroth is excited to see the Undiagnosed Hackathon continue, because she knows how valuable it is for families to get answers and for the international community to come together and collaborate.
