Michele Herndon’s son Mitchell began developing symptoms of an ultra-rare neurological condition in 2012. He went for five years without answers and in 2017, enrolled in the Undiagnosed Diseases Network, an NIH-funded research study that seeks to diagnose people with the most puzzling conditions. He was diagnosed with the genetic disease Mitchell syndrome, which was named for him. He died from the disease in 2019. Herndon not only started the Mitchell & Friends Foundation but is today the program director of the Undiagnosed Diseases Network Foundation. There she has helped establish the UDNF’s new Patient Navigator Program, which is designed to answer general question undiagnosed patients may have, connect them to resources, and guide them through the UDN process. We spoke to Herndon and F. Sessions Cole, secretary of Undiagnosed Disease Network Foundation and professor of Pediatrics at Washington University School of Medicine, about the diagnostic odyssey, the work of the Undiagnosed Disease Network and the Undiagnosed Disease Network Foundation, and how the new Patient Navigator program works.