Title: Shared Resource Core Summary/abstract Myotonic dystrophy (DM) and facioscapulohumeral muscular dystrophy (FSHD) have multisystem complications that are serious, progressive, and often disabling. A better understanding of the novel mechanisms of DM and FSHD has led to identifying several good therapeutic targets. Advances have occurred more quickly than expected with several experimental drugs in development or clinical trials. There is now renewed urgency to enhance the translational resources needed to facilitate current and future studies and clinical trials. To achieve this goal, several aims of the shared resource core propose to sustain and enhance the resources of the oldest and most comprehensive Registry for patients with myotonic dystrophy type 1 (DM1), type 2 (DM2), and FSHD. The National Registry for DM and FSHD Patients and Family Members has facilitated research for 23 years with the same overarching goals to assist researchers in the recruitment of patients for clinical studies and trials, to develop an extensive database of longitudinal patient information, and to promote community outreach with patients, family members, clinicians, and researchers. Core Registry methods include patient-reported questionnaires and curated medical records, annual surveys to track disease progression, and researchers applying to access data or for assistance with recruitment. Overall, the Registry has functioned effectively, but several changes are needed to make it more effective in the future. First, the core activity and methods of the National Registry described above will be sustained to help maintain two-way communication between researchers and patients and to help advance research on muscular dystrophy. A second aim is to expand the Registry dataset and prepare for targeted recruitment based on clinical and genetic characteristics in DM1. Highlights of this aim include incorporating remote genetic and clinical characterization of Registry members with DM1, including quantified assessments of strength, function, and myotonia. A third aim is to expand & diversify Registry engagement and prepare for comparative studies of long-term drug effects. Specific tasks include recruiting patients from neuromuscular clinics not typically near DM and FSHD research centers, translating forms to Spanish, and expanding online presence and enrollment. A fourth goal is to promote research on understudied manifestations of DM and FSHD, which have important implications for quality of life. This goal builds upon current data in the Registry on several topics important to patients, such as gastrointestinal manifestations in DM, vision problems in FSHD, and neoplasms in DM. A key proposal here is to add data to the Registry on women’s health in DM and FSHD and expand data collection on smooth muscle involvement in DM and gastrointestinal and genitourinary assessments in FSHD. Overall, the Shared Resource Core will serve the needs of researchers in our Center...