Which syndrome is characterized by craniosynostosis, maxillary hypoplasia, and symmetric syndactyly of the hands and feet?

• A. Apert syndrome
• B. Crouzon syndrome
• C. Pfeiffer syndrome
• D. Down syndrome

Answer: (A)

This pattern points to Apert syndrome: premature fusion of skull sutures (craniosynostosis) combined with midface (maxillary) hypoplasia and symmetric syndactyly of the hands and feet. The hallmark feature is the complex, often extensive, fusion of digits along with cranial and facial abnormalities. Apert syndrome most commonly results from FGFR2 mutations and is inherited in an autosomal dominant manner. The craniosynostosis explains the abnormal head shape and potential intracranial issues, while maxillary hypoplasia leads to midface retrusion and dental crowding. The symmetric syndactyly of both hands and feet distinguishes it from other craniosynostosis syndromes where syndactyly is absent or not as characteristic. Crouzon syndrome involves craniosynostosis and facial features but typically lacks syndactyly; Pfeiffer can have craniosynostosis with broad thumbs and toes and variable, not classically symmetric syndactyly; Down syndrome does not feature craniosynostosis with this pattern of syndactyly.