On plain radiograph of a child's wrist, the Greulich-Pyle atlas is used. A 10-year-old girl's bone age matches a skeletal age of 13 years (3 SD above mean). This advanced bone age in the context of precocious puberty, café-au-lait spots, and fibrous dysplasia is seen in which syndrome?
- A Beckwith-Wiedemann syndrome
- B McCune-Albright syndrome ✓
- C Neurofibromatosis type 1
- D Turner syndrome
Explanation
McCune-Albright syndrome is a non-hereditary mosaic disorder caused by postzygotic activating GNAS mutations, presenting with the triad of polyostotic fibrous dysplasia (with the classic shepherd's crook deformity and ground-glass matrix on X-ray), café-au-lait spots with irregular ('coast of Maine') borders, and endocrinopathies including gonadotropin-independent precocious puberty (which causes advanced bone age). NF1 causes café-au-lait spots with smooth borders but not fibrous dysplasia-mediated precocious puberty. Turner syndrome causes delayed bone age. Beckwith-Wiedemann involves overgrowth syndromes without bone dysplasia.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.