Of Bone | Fibrous Dysplasia

Osteoblasts (bone-forming cells) fail to mature, producing disorganized "woven bone" instead of strong "lamellar bone".

Affects a single bone. It accounts for about 70-80% of cases and is often asymptomatic until discovered incidentally on an X-ray.

Affects multiple bones. This form typically presents earlier in childhood and is more severe.

The condition stems from a in the GNAS gene . This mutation is not inherited from parents but occurs spontaneously during early embryonic development.

Symptoms vary widely based on the location and extent of the lesions: Fibrous Dysplasia - StatPearls - NCBI Bookshelf

Fibrous dysplasia (FD) is a rare, non-inherited bone disorder where normal bone marrow is replaced by abnormal, fibrous connective tissue. This makes the affected bones weak, prone to fractures, and susceptible to deformities. Pathophysiology and Genetics

Fibrous dysplasia is categorized by how many bones it affects:

A triad of polyostotic FD, café-au-lait skin spots (often with jagged "Coast of Maine" borders), and hyperfunctioning endocrine issues like precocious puberty. Symptoms and Complications