Introduction to Fibrodysplasia ossificans progressiva (FOP, Münchmeyer syndrome)

Fibrodysplasia ossificans progressiva (FOP, Münchmeyer syndrome)

  • First mentioned in England around 1740
  • Orphan disease, approx. one patient per 2 million individuals
  • Approx. 600 cases are documented
  • Autosomal dominant
  • Average life span: 45 years
  • Early indicator: deformed big toes


  • Progressive incidents of inflammation, followed by differentiation of inflamed tissue into bone
  • Patients evolve a “second skeleton”, leading to progressive immobilization and eventually, death
  • In 2006, a landmark study showed that a point mutation in the ALK2 receptor is linked to FOP (Shore et al., 2006)
  • ACVR1/ALK2 is part of the family of type I BMP receptors (BMPRs)
  • BMPRs play a crucial role in bone formation during development
  • The study suggests that the identified ALK2 R206H mutation leads to receptor hyperactivation