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Osteogenesis Imperfecta (OI)

Osteogenesis Imperfecta (OI) is a genetic condition caused by defects in the formation of bone, characterized by fractures with minimal or absent trauma along with a range of clinical features. OI has a prevalence of approximately 6 to 7 per 100,000, is present in all racial and ethnic groups, and is inherited in a mostly autosomal dominant fashion.

Approximately 90% of OI cases are caused by defects in type I collagen, which is a component of bone that provides structural stability. In individuals with OI types I-IV, 90% have mutations in either the COL1A1 or COL1A2 genes. A mutation in either of these genes may result in a decrease in the amount or quality of type I collagen that is produced. When type I collagen is improperly formed, the bone loses much of its strength and fractures easily. In addition to bone fractures, patients can have short stature, hearing loss, abnormal tooth development, blue sclerae, and various bony deformities.

Reasons for Referral

  • In comprehensive work-up of non-accidental trauma (NAT)
  • An adult or child with multiple fractures of unknown etiology
  • Confirmation of a clinical diagnosis of OI
  • Confirmation of a specific mutation(s) for prenatal diagnosis/family planning
  • Prenatal testing for known familial mutation in a fetus

Testing Methods

Full sequence analysis of COL1A1 and COL1A2 genes.

Turn Around Time

7 days or fewer

Specimen Requirements and Shipping/Handling

Blood: A single tube with 1-5 mL whole blood in EDTA (lavender top).

Amniotic Fluid: 30 mL of clear amniotic fluid. The sample also needs to be accompanied by 1-5 mL of maternal blood in EDTA (lavender top) for maternal cell contamination studies.


Blood: Store blood at 4°C until shipment. Ship at ambient temperature in an insulated container via overnight delivery within 96 hours of collection.

Amniotic Fluid: Store fluid at 4°C until shipment. Ship at ambient temperature in an insulated container via overnight delivery within 4 hours after collection. For prenatal samples please contact lab prior to sending sample.

Send Specimen(s) to:

Genetics Center
211. S Main Street
Suite AA
Orange, CA 92868
Tel: (714)288-3500


CPT Codes

CPT’s: 81408x 2, G0452

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