Osteogenesis Imperfecta



  • Inherited abnormality of procollagen amino acid sequence
  • “Brittle bone disease”
  • Bone hypomineralization and incomplete ossification result in brittle bones
  • Incidence is 1/20,000 live births
  • Abnormal collagen affects all connective tissue to varying degrees
  • Time course is variable:
    • Most cases involve fractures during childhood followed by quiescence during adolescence and early adulthood


  • Procollagen defects result in abnormalities of bone and connective tissue matrix
  • Defects in different sites on procollagen protein chain result in more severe forms
  • Defects are inherited, either autosomal recessive (generally milder) or autosomal dominant (more severe)
  • Lethal cases involve sporadic or new mutations
  • Ehlers–Danlos syndrome involves mutations of the same procollagen protein in different locations

Pediatric Considerations
  • Most cases involve pathologic fractures during childhood
  • Multiple fractures often initiate evaluation for nonaccidental trauma, but the possibility of pathologic fractures also should be considered

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