title: Heterotopic ossification.
abstract: Heterotopic ossification, the formation of bone in soft tissue, requires inductive signaling pathways, inducible osteoprogenitor cells, and a heterotopic environment conducive to osteogenesis. Little is known about the molecular pathogenesis of this condition. Research into two rare heritable and developmental forms, fibrodysplasia ossificans progressiva and progressive osseous heteroplasia, has provided clinical, pathologic, and genetic insights. In fibrodysplasia ossificans progressiva, overexpression of bone morphogenetic protein 4 and underexpression of multiple antagonists of this protein highlight the potential role of a potent morphogenetic gradient. Research on fibrodysplasia ossificans progressiva also has led to the identification of the genetic cause of progressive osseous heteroplasia: inactivating mutations in the alpha subunit of the gene coding for the stimulatory G protein of adenylyl cyclase. Better understanding of the complex developmental and molecular pathology of these disorders may lead to more effective strategies to prevent and treat other, more common forms of heterotopic ossification.
authors.affiliation: Departments of Orthopaedic Surgery and Medicine, The University of Pennsylvania School of Medicine, Silverstein 2, 3400 Spruce Street, Philadelphia, PA 19104-5283, USA.
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Kaplan
authors.forename: David L
authors.initials: DL
authors.lastname: Glaser
authors.forename: Nader
authors.initials: N
authors.lastname: Hebela
authors.forename: Eileen M
authors.initials: EM
authors.lastname: Shore
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D019485:Bone Morphogenetic Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D015870:Gene Expression; D020022:Genetic Predisposition to Disease; D006801:Humans; D015994:Incidence; D008297:Male; D009221:Myositis Ossificans / Q000453:epidemiology / Q000235:genetics* / Q000503:physiopathology*; D009999:Ossification, Heterotopic / Q000453:epidemiology / Q000235:genetics* / Q000503:physiopathology*; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution
chemical_list: D019485:Bone Morphogenetic Proteins