A rare benign primary bone dysplasia characterized by progressive replacement of normal bone and marrow with fibrous connective tissue in either one (monostotic) or multiple (polyostotic) bones. Clinical manifestations depend on the anatomic location of the replacement and may include bone pain deformities pathological fractures and cranial nerve deficits.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version February 2026
Newly diagnosed with
Fibrous dysplasia of bone?
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Advocacy Organizations
FD/MAS Alliance (incorporated as Fibrous Dysplasia Foundation)
The FD/MAS Alliance is the leading 501(c)(3) nonprofit that serves individuals and caregivers affected by fibrous dysplasia/McCune-Albright syndrome (FD/MAS), a rare bone and endocrine disease. As a community-driven organization, we advance research, foster the development of evidence-based treatments, provide critical education, and amplify the voices of those impacted by FD/MAS. Join us.
The Chandler Project
The Chandler Project brings awareness and shines a light on transformative research surrounding achondroplasia and other skeletal dysplasias by offering support to a global community and network of patients, parents, and caregivers seeking information on scientific discoveries, pharmaceutical advancements and surgical treatment options.
Wave of Support, Inc
Empowering those affected by bleeding disorders and other rare disease through advocacy, resources, education, and support
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Clinical Trials
For a list of clinical trials in this disease area, please click here.