Rare disease patients face a variety of challenges, but one of the most significant obstacles to health equity is the “diagnostic lag.” This event will focus on the theme of “diagnostic lag,” with experts from various fields, including physicians, patient group, and AI companie, discussing the issue from multiple perspectives to deepen understanding of the challenges faced by rare and intractable disease patients.

Opening
Key Note
・Exploring and Discussing Rare Diseases with Stakeholders
・Expectations for Whole Genome Testing in Critically Ill Newborns
・Innovation in Medical Digital Technology
・The Path to Overcoming Rare and Intractable Diseases Through Patient Data
Panel Discussion
・Solving the Diagnostic Lag and Moving Towards the Future
Closing

【Reflection】
This event focused on the significant challenge of the "diagnostic lag" in rare diseases—the delay many patients face from the onset of symptoms to receiving a definitive diagnosis. Experts from a variety of backgrounds, including patient advocacy group, medical professionals, AI company, and intermediary organization, engaged in an in-depth discussion from multiple perspectives.

Yukiko Nishimura highlighted the reality of the “diagnostic lag” for rare disease patients, reporting that, on average, it takes 3.4 years to receive a correct diagnosis. Notably, about 35% of patients wait more than five years, and nearly 60% experience misdiagnoses. She emphasized that solving this challenge requires open exchange and collaboration among all stakeholders.

Toshiki Takenouchi explained that approximately 10% of critically ill newborns in NICUs have genetic diseases, underscoring the importance of early diagnosis through whole genome sequencing. He presented achievements showing that, for infants whose diagnoses were challenging even for experienced neonatologists, about half had their genetic causes identified through genomic analysis. He also noted that fostering a society without discrimination requires legal reforms and broader public understanding.

Shinsuke Muto discussed the potential of AI to detect rare diseases from patient interviews and imaging data, as well as the development of SaMD (Software as a Medical Device) and telemedicine. These technological advances enable integrated analysis of medical information, improve access to specialists, and support more accurate diagnoses. However, He also addressed ongoing challenges, including the difficulty of data collection, as well as ethical and security considerations.

Based on dialogue with patient communities, Yoshihisa Yamano described persistent issues such as delays in diagnosis, shortages of specialists, and the isolation or discrimination faced by patients. He stressed that each patient’s medical data represents a powerful tool to change the future, and explained that establishing and utilizing patient registries can be key to advancing treatment development and addressing rare disease challenges.

In the panel discussion, joined by Hiroshi Oguro and Misako Hamamura, participants explored solutions to the diagnostic lags. The conversation confirmed the importance of not only implementing new diagnostic technologies such as AI and genomic testing but also strengthening national policies and disseminating accurate information to the public. The collection of medical data before definitive diagnosis and closer cooperation with patients were also recognized as essential. Participants strongly agreed that wide social understanding is indispensable to resolving the diagnosis lag.
The event reaffirmed that the "diagnosis lag" is not merely a medical problem but a broader societal issue that impacts patients’ quality of life, social participation, and the future development of medical technology. The event was attended by approximately 70 rare disease patients and general participants in person, with over 300 additional views online. It is hoped that this event will further advance dialogue and action to eliminate the diagnosis lag for rare diseases.

Reference 1) Alexion Pharma GK, “White Paper on Rare Diseases: The Reality of Diagnostic Lags and Recommendations for Resolution”
https://alexionpharma.jp/-/media/alexionpharma_ajp/expo2025/rare-disease-wp_alexion_20250514.pdf


【Post EXPO Initiatives】
There are more than 10,000 types of rare diseases across the globe, affecting an estimated 400 million people worldwide. Approximately 80% of these diseases are linked to genetic abnormalities, and about half of the patients are diagnosed during childhood. Individuals with rare diseases and their families face numerous challenges in daily life and in accessing appropriate medical care, and health equity remains insufficiently addressed. On average, it takes about 3.4 years for a rare disease patient to receive a definitive diagnosis—a phenomenon known as the diagnostic lag. Furthermore, even after diagnosis, established treatment options exist for only around 10% of rare diseases.

In an effort to address these issues, Alexion Pharma G.K. released a white paper on May 14, 2025, entitled “White Paper on Rare Diseases: The Realities of Diagnostic Lag and Proposals for Resolution*—Enabling Health Equity Through Cutting-edge Technology and Societal Collaboration.” The white paper identifies diagnostic lag as a significant barrier to achieving health equity for rare disease patients. It provides quantitative data on the burdens caused by diagnostic lag, including direct medical costs, and presents realistic and actionable mid- to long-term strategies for faster diagnosis and improved equality in medical access.

The white paper presents the following six key recommendations:
• Expand the range of diseases included in newborn mass screening and promote the necessary infrastructure to introduce whole genome sequencing for critically ill newborns.
• Enhance the use of AI diagnostic support tools (such as SaMD) to help physicians make early discoveries of rare diseases.
• Establish Centers of Excellence for rare diseases to strengthen the connections between general practitioners and specialists.
• Improve infrastructure so that rare disease data can be leveraged for early diagnosis.
• Ensure patient voices are reflected in policy development by promoting greater participation from patient advocacy groups and supporting the financial foundations needed for their activities.
• Incorporate measures to resolve diagnostic lag and diagnostic loss for rare diseases into core government initiatives and strategies.

At the event, diverse specialists—including medical specialists, patient advocate, AI company, and intermediary organization —held in-depth discussions on the white paper’s analysis and recommendations. Alexion is dedicated to sharing the outcomes of the white paper and the event more widely to stimulate societal dialogue regarding rare diseases and diagnostic lag. By advancing collaboration with all stakeholders, Alexion aims for a future where health equity is achieved, and all those affected by rare diseases can benefit from timely and appropriate medical care.


*White Paper on Rare Diseases: The Reality of Diagnostic Lags and Recommendations for Resolution
https://alexionpharma.jp/-/media/alexionpharma_ajp/expo2025/rare-disease-wp_alexion_20250514.pdf

Alexion Pharma GK