(BBDC Administrative Core) The BBDC administrative core will coordinate and implement the BBDC under the direction of the overall PI Dr. Brendan Lee, co-PI Tracy Hart, and Clinical Team Liaison Dr. V. Reid Sutton. It will also coordinate the interactions among the clinical sites, cores, and the patient advocacy site. To achieve this, the Core will track and facilitate funds transfer and subcontracts between participating sites, schedule and prepare agendas for monthly teleconferences separately for the executive committee, the PI-steering committee, and site coordinators. The Core will coordinate the annual BBDC in person meeting in conjunction with the annual Osteogenesis Imperfecta Foundation Scientific Meeting, and facilitate the annual Geisman training fellowship competition. Finally, the core will administer and review a) clinical training fellowships by the OIF, b) pilot project applications, c) requests for access to bio-specimens collected within the longitudinal study, d) centralized radiographic reading and quality/assessment of imaging sites, and coordinate e) the annual external advisory committee review and f) administrative preparation of documents for single Institutional Review Board (sIRB) and Data and Safety Monitoring Board (DSMB) review. The Core will be responsible for all communications between the BBDC and the broader RDCRN and Participant communities.