Leg pain in an infant.

Area of Science:

• Pediatric Orthopedics
• Medical Genetics

Background:

• Distinguishing nonaccidental trauma from underlying medical conditions like osteogenesis imperfecta (OI) is critical in pediatric fracture cases.
• Multiple fractures in infants raise concerns for both trauma and metabolic bone diseases, necessitating a thorough differential diagnosis.

Observation:

• An 11-month-old infant presented with a femur fracture, alongside evidence of healing humeral and rib fractures.
• Comprehensive metabolic workup, including urine organic acids, serum amino acids, and vitamin D levels, was performed.
• Genetic sequencing targeted COL1A1 and COL1A2 genes to investigate potential inherited bone disorders.

Findings:

• Genetic analysis identified a mutation in the COL1A1 gene.
• This mutation is consistent with a diagnosis of osteogenesis imperfecta type I.
• The diagnostic process successfully ruled out nonaccidental trauma as the sole cause of the fractures.

Implications:

• This case highlights the importance of genetic testing in evaluating pediatric fractures, especially with multiple fracture patterns.
• Accurate diagnosis of OI is crucial for appropriate management, genetic counseling, and preventing misdiagnosis of abuse.
• Understanding the genetic basis of OI aids in predicting disease severity and long-term prognosis.