Diagnostic challenges in distinguishing osteogenesis imperfecta from nutritional rickets in a 5-week-old preterm neonate with multiple fractures and rachitic rosary: A case report from Northern Tanzania

Background: Differentiating osteogenesis imperfecta from nutritional rickets in neonates is challenging in resource-limited settings because both conditions may present with bone fragility, fractures, and costochondral beading.
Case presentation: A 5-week-old male preterm neonate born at 33 weeks’ gestation was admitted for prematurity-related care. On day 5 of life, he developed swelling and reduced movement of the limbs without a history of trauma. Examination revealed rachitic rosary and bilateral blue-grey sclera. Skeletal survey demonstrated fractures of both humeri and the right femur, with generalized osteopenia and thin cortices. Haemoglobin was 11.7 g/dL and serum calcium was borderline low at 2.13 mmol/L. Serum phosphate, alkaline phosphatase, and 25-hydroxyvitamin D could not be measured because reagents were unavailable. Although nutritional rickets was initially considered, the blue sclera, fracture pattern, and radiological osteopenia favoured osteogenesis imperfecta with possible concurrent rickets. There was no clinical or historical evidence of accidental or non-accidental trauma.
Conclusion: Multiple fractures in a neonate with rachitic rosary and normal or borderline-low calcium should prompt consideration of osteogenesis imperfecta, particularly when blue sclera and generalized osteopenia are present. In settings where advanced biochemical and genetic tests are unavailable, careful clinical examination, serum calcium measurement, and skeletal survey can support early provisional diagnosis.