he UDNF works closely with the UDN, a research study backed by the National Institutes of Health (NIH) that brings together clinical and research experts from across the United States to evaluate undiagnosed patients. The UDN consists of clinical sites, model organisms screening centers (MOSCs), a coordinating center, a sequencing core, and central biorepository. Patients can submit a case directly online using the UDN’s case submission gateway.