OpenAI’s o3 model helped diagnose 18 children with unsolved rare diseases

Boston Children’s Hospital and Harvard researchers used OpenAI’s o3 Deep Research model to reanalyze 376 unsolved pediatric rare disease cases, according to a study published Wednesday in NEJM AI.nejm
The AI tool helped clinicians identify 18 new diagnoses spanning neurodevelopmental disorders, neuromuscular disease, and early-onset psychosis by synthesizing genetic and clinical data.digg
OpenAI committed $50 million to the hospital’s AI efforts, which have yielded more than 40 total rare disease diagnoses previously deemed unsolvable, according to the hospital.openai

OpenAI’s o3 Model Helps Diagnose 18 Children With Previously Unsolved Rare Diseases

Researchers at Boston Children’s Hospital and Harvard used OpenAI’s o3 Deep Research model to identify 18 new diagnoses among children whose rare genetic diseases had stumped clinicians for years, according to a study published Wednesday in NEJM AI.nejm

How the Study Worked

The team reanalyzed 376 de-identified pediatric cases that had already undergone genetic testing and expert review without yielding a diagnosis. Using the o3 Deep Research model to synthesize genetic data, clinical presentations, and medical literature, clinicians were able to identify diagnoses spanning neurodevelopmental disorders, rare neuromuscular disease, sudden unexpected death in pediatrics, and early-onset psychosis.digg

The tool is designed to assist clinicians and researchers in navigating complex medical information rather than serve as a direct consumer diagnostic product. John Brownstein, Chief Innovation Officer at Boston Children’s Hospital, has described the underlying challenge as one of cognitive limits rather than effort.

“We combine genetic information, phenotypic information, literature search, and the reasoning of AI to deliver diagnoses to families that were once left without any answers,” Brownstein said.openai

A Broader Push Into AI-Assisted Medicine

The NEJM AI publication represents the peer-reviewed validation of a broader initiative at Boston Children’s. The hospital announced in late May that its AI efforts had resulted in more than 40 rare disease diagnoses to date that were previously considered unsolvable. The collaboration with OpenAI, which committed $50 million in support to the hospital’s efforts, has been underway since early 2025.linkedin

Boston Children’s has embedded AI across its operations, with more than one-third of employees now using AI tools in daily work. The hospital reports approximately 60,000 hours saved across AI-enabled workflows, equivalent to more than $7 million in redeployed labor.openai

What It Means for Rare Disease Patients

Rare diseases collectively affect an estimated 300 million people worldwide, yet individual conditions are often so uncommon that even specialists at leading institutions struggle to reach diagnoses. Many families endure years-long “diagnostic odysseys” before receiving answers.

“This was unthinkable before, but is now providing hope to so many families,” Brownstein said.openai

The researchers emphasized that the AI functions as a tool to augment human expertise, not replace it — each diagnosis still required clinician verification and interpretation.digg