Which term matches the description 'brittle bone disease'?

• A. Osteoporosis
• B. Endocarditis
• C. Osteogenesis imperfecta
• D. Scoliosis

Answer: (C)

Brittle bone disease is osteogenesis imperfecta, a genetic condition in which mutations disrupt type I collagen, the protein that gives bone its strength. When collagen is defective, bones fracture easily with little or no trauma, which is why this term specifically describes brittle bones. This differs from osteoporosis, which is a loss of bone density often linked to aging or hormonal changes and isn’t caused by a collagen defect. Endocarditis is an infection of the heart valves, and scoliosis is a sideways curvature of the spine, neither of which describe fragile bones. Knowing that bone fragility here comes from defective collagen helps you identify osteogenesis imperfecta as the correct term.