A 2-year-old boy presents with his third bone fracture within the past several months. There is no history or evidence of trauma. Several close family members have been similarly affected. 2 of the affected family members are also hard of hearing. The child is small for his age, and the sclerae are tinged a bluish color. Radiographs reveal generalized osteopenia and evidence of multiple fractures, both old and new. What is the most probable diagnosis?
High-Yield Explanation
Osteogenesis imperfecta Most common genetic cause of osteoporosis Types I -V a Autosomal dominant disorder Etiopathogenesis: Mutations in COL1A1 or COL1A2 that code for type I collagen Structural or quantitative defects in type I collagen Connective tissue abnormalities in bones, teeth, skin & eyes Clinical features: Triad - Blue sclera - Deafness - Recurrent Fractures Rx - I/v Bisphosphonates eg Pamidronate