A fibrodysplasia ossificans progressiva patient with a rare missense mutation in ACVR1 detected on 18F-FDG PET/CT

Fibrodysplasia ossificans progressiva (FOP) is an exceedingly rare human genetic disorder characterized by the progressive and incapacitating formation of ectopic bone outside the skeleton. We report a case of FOP patient with mutations within the ACVR1 gene (c.982G > A; p.G328R). ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) was carried out for disease assessment. Previous studies have shown increased FDG uptake in regions of heterotopic ossification (HO) in FOP. However, in our study, the PET/CT features demonstrate that active ossificans exhibit increased ¹⁸F-FDG uptake, whereas end-stage ossifications do not. Collectively, ¹⁸F-FDG PET/CT emerges as a prospective approach to evaluate medication efficacy in the early stages, directing early intervention and pharmacological management of FOP before ossifications formation.