Fig. 1

Key components of an Undiagnosed Diseases Program. This diagram presents a stepwise process that broadly corresponds to components of the US Undiagnosed Diseases Program [14], as well as how these steps have been adapted or implemented in other Undiagnosed Diseases Programs worldwide [11, 15,16,17,18,19,20,21,22,23, 29, 31, 37]. Green boxes denote elements of each stage that necessitate patient involvement while blue boxes represent research components