Hatsell et al (Sci Transl Med. 2015 Sep 2;7(303):303ra137. doi: 10.1126/scitranslmed.aac4358) recently published very exciting work on the mechanism of the common ACVR1 gene mutation underlying fibrodysplasia ossificans progressive (FOP). This mutation confers the ability of the BMP 1 receptor ACVR1 to respond to the inflammatory response ligand Activin A, and induce bone formation. This mechanism explains why individuals with FOP are not born with heterotopic bone, but develop this over time and characteristically after trauma.
This offers a novel directed mechanism of treatment, in that mice with a conditional ACVR1 R206H can be spared from heterotopic bone formation via introduction of an antibody directed at ActivinA1.
Hilary Vernon, MD PhD