Home Fibrodysplasia ossificans progressive (FOP)

Fibrodysplasia ossificans progressive (FOP)

Defining Characteristics

Soft tissue swelling that progressively turns to bone esp at sites of injury (avoid trauma!!); malformed great toe, progressive heterotopic ossification pattern; spares heart/ diaphragm/ extraocular muscles

Disease Development

Inflammatory swelling of soft tissues that eventually transforms into encasement of bone during first decade of life via endochondral ossification
Missense mutation of ACVR/ALK2 inactivates binding site for inhibitor (FKBP12), causing excessive and constitutive BMP stimulation

Potential Causes

Excessive BMP stimulation –> increased osteoblast formation




Patients usually die of R heart failure, Pulmonary HTN
Require wheelchair by 3rd decade