Differential Diagnosis
- Single most likely diagnosis:
- B) Fibroblast growth factor 3: The clinical presentation of bowleg deformity, metaphyseal flaring, inverted V-shape distal femoral physis, and a disproportionately long fibula is highly suggestive of Achondroplasia, the most common form of short-limbed dwarfism. Achondroplasia is caused by a defect in the fibroblast growth factor 3 (FGFR3) gene.
- Other Likely diagnoses:
- A) Cartilage oligometric matrix protein: This is associated with pseudoachondroplasia, a condition that also presents with short-limbed dwarfism and joint abnormalities, but the X-ray findings and clinical presentation are not as typical as those seen in achondroplasia.
- E) Type 2 collagen: Defects in type 2 collagen are associated with various forms of spondyloepiphyseal dysplasia and Kniest dysplasia, which can present with short stature and skeletal abnormalities, but the specific X-ray findings and clinical features described are more characteristic of achondroplasia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- D) Type 1 collagen: While osteogenesis imperfecta (caused by defects in type 1 collagen) primarily presents with bone fragility and blue sclerae, some types can have a more mild presentation with short stature and skeletal deformities. Missing this diagnosis could lead to inadequate management of fracture risk and other complications.
- Rare diagnoses:
- C) Sulfate transport protein: This is associated with diastrophic dysplasia, a rare form of short-limbed dwarfism with distinct clinical and radiographic features, including hitchhiker thumb and cystic changes in the ears. The presentation described does not closely match diastrophic dysplasia, making it a less likely consideration.