Is the UDN N-of-1 Enterprise Ethically Justifiable?

The Undiagnosed Diseases Network is a national consortium of clinicians and researchers working to promote diagnostic research and accurately diagnose patients with rare diseases, many of whose conditions have long gone undiagnosed. This endeavor's importance should not, however, stop us from asking good ethics and policy questions about whether and when N-of-1 diagnostic research is justifiable. This article poses and considers questions about informed consent, information privacy, and justice in this very specific kind of human subjects research.