(Career Enhancement Core) A key goal of the Rare Disease Clinical Research Network (RDCRN) is to train the next-generation of rare disease clinical/translational investigators. The Brittle Bone Disorders Consortium (BBDC) has made significant progress towards contributing to this mission. Over the past five years, the BBDC provided Geisman research fellowship funding to seven highly-qualified early-stage investigators (out of a total of 14 funded by the OIF). Additionally, by leveraging Institutional resources, the BBDC investigators mentored another 10 young investigators in research projects directly related to OI. Furthermore, 20 trainees received travel awards to attend the annual scientific meetings of the OIF and the RDCRN's Conference on Clinical Research for Rare Diseases where they had opportunities to present their scientific work. BBDC enhancement activities also ensured that the trainees actively engage with the OIF, the primary patient advocacy group (PAG), and to interact with individuals and families affected by OI. The success of these strategies is best exemplified by the fact that trainees supported by the BBDC have published over 80 publications in the short span of time coinciding with years 1-5 of the BBDC. In addition to these career enhancing activities, the BBDC, in partnership with the OIF, and professional organizations like the American Society for Bone and Mineral Research (ASBMR), National Osteoporosis Foundation, and the Rare Bone Disease Alliance (RBDA), has successfully disseminated information about rare bone diseases and OI to patients, healthcare professionals, and industry partners, thus broadening the impact of the education and training mission of the consortium. The BBDC Career Enhancement Core (CEC) proposes to expand upon the previous training achievements by recruiting and supporting medical students, dentists in training, predoctoral fellows, postdoctoral fellows, genetic counselors, and junior faculty who are interested in rare diseases. To help facilitate a career in rare diseases research, the BBDC CEC will provide a range of career enhancement activities including: 1) procuring protected research time for postdoctoral fellows and junior faculty through the Michael Geisman Fellowship from the OIF, 2) providing didactic training relevant to rare diseases research, 3) engaging the trainees to utilize the data from the longitudinal study to complement the mechanistic data generated in the laboratory, 4) providing opportunities to showcase their research work both within and outside the consortium, and 5) partaking in the community and educational outreach programs of the OIF. The CEC will leverage numerous training resources at its site institutions including: 1) NIH funded Intellectual and Developmental Disabilities Research Centers (IDDRC), Clinical and Translational Science Awards (CTSA), and Training Grants (e.g., K12, K30, and T32 mechanisms), 2) medical and graduate school programs, and 3) educational outreach program of the OIF, to accomplish its goals.