osteogenesis imperfecta

Autosomal dominant disease.

Synopsis

 systemic anomalies

• perinatal death
• premature birth
• nonimmune hydrops
• low birth weight

 ocular anomalies

• blue sclerae

 craniofacial anomalies

• beaked nose
• large fontanelles
• platyspondyly

 skeletal anomalies

• short limb dwarfism
• beaded ribs
• numerous multiple fractures present at birth
• soft calvaria
• absent calvarial mineralization
• hips usually flexed and abducted (frog-leg position)
• flattened acetabulae and iliac wings
• tibial bowing
• broad crumpled long bones
• telescoped femur

 thin skin
 congestive heart failure
 pulmonary insufficiency

Types

 Osteogenesis imperfecta type 1 (OI type 1)is a dominantly inherited, generalized connective tissue disorder characterized mainly by bone fragility and blue sclerae.
 Osteogenesis imperfecta type 2 (OI type 2)
 Osteogenesis imperfecta type 3
 Osteogenesis imperfecta type 4 (MIM.166220)
 Osteogenesis imperfecta with opalescent teeth (MIM.166240)

Etiology

 mutations in COL1s genes

• mutations in COL1A1 gene (MIM.120150)
• mutations in COL1A2 gene (MIM.120160)

 gonadal and somatic mosaicism reported in parent

References

 Millington-Ward S, McMahon HP, Farrar GJ. Emerging therapeutic approaches for osteogenesis imperfecta. Trends Mol Med. 2005 Jun;11(6):299-305. PMID: 15949772