Which feature is most characteristic of osteogenesis imperfecta?

• A. Frequent fractures with minor trauma
• B. Osteoarthritis
• C. Hyperparathyroidism
• D. Severe altitude sickness

Answer: (A)

Osteogenesis imperfecta is defined by brittle bones from a defect in type I collagen, which weakens the bone matrix. That makes bones susceptible to fracture even with minimal, everyday stress. So the hallmark feature is frequent fractures with minor trauma, which reflects the overall skeletal fragility of this condition.

Osteoarthritis involves wear-and-tear of joints over time, not a systemic fragility of the skeleton. Hyperparathyroidism causes metabolic bone changes from excess parathyroid hormone, but it isn’t the defining issue in OI. Severe altitude sickness is related to hypoxia at high elevations, unrelated to bone integrity.