A stillborn fetus has extremely short limbs and a narrow thorax. Radiograph shows bowed femurs with a dumbbell or 'telephone receiver' appearance and cloverleaf skull deformity. Which skeletal dysplasia is this?
- A Achondroplasia
- B Osteogenesis imperfecta type II
- C Thanatophoric dysplasia ✓
- D Chondroectodermal dysplasia
Correct answer: C. Thanatophoric dysplasia
Explanation
Thanatophoric dysplasia is the commonest lethal neonatal skeletal dysplasia, characterised radiologically by severe rhizomelic shortening, bowed telephone-receiver femurs, platyspondyly, a narrow chest, and frequently a cloverleaf skull. Achondroplasia is non-lethal and shows champagne glass pelvis with trident hand but straight femurs. Osteogenesis imperfecta type II shows multiple fractures and crumpled bones rather than uniform bowing. Chondroectodermal dysplasia features polydactyly and cardiac defects.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.