Rapid Progression of Heterotopic Ossification in Severe Variant of Fibrodysplasia Ossificans Progressiva with p.Arg258Gly in ACVR1: A Case Report and Review of Clinical Phenotypes

Figure 2

Time-course series of heterotopic ossification (HO). (a–d) Front chest and upper limbs. (e–h) Back chest. (a, e) At 10 months of age, HO was not observed. (e) Cervical vertebrae fusion was observed. (b, f) At 26 months of age, HO was observed from the bilateral axillary and humerus. (c, g) At 42 months, HO was observed between the humerus and radius and between the humerus and thoracic cage. (d, h) Scoliosis due to multiple HO occurrences was observed at 106 months. (i–m) Lumbar spine and pelvis. (i) At 26 months of age, HO was not observed. (j) At 42 months of age, HO was observed from the left transverse process of the lumbar spine. (k) At 78 months of age, HO was observed from the neck of the left femur and connected the left transverse process and left femur thereafter. (l) At 106 months of age. (m) At 121 months of age.