The Rare Diseases Clinical Research Network (RDCRN) is an initiative of the Office of Rare Diseases Research (ORDR). RDCRN is funded by the ORDR, the National Center for Advancing Translational Sciences and collaborating institute centers. The RDCRN is designed to advance medical research on rare diseases by providing support for clinical studies and facilitating collaboration, study enrollment and data sharing. Through the RDCRN consortia, physician scientists and their multidisciplinary teams work together with patient advocacy groups to study more than 200 rare diseases at sites across the nation.