A neonate with congenital heart defect, ambiguous genitalia, and rocker-bottom feet undergoes chromosomal analysis showing 47,XY,+18. Which cardiac defect is MOST characteristic of trisomy 18 (Edwards syndrome)?
- A Atrioventricular septal defect (AVSD)
- B Tetralogy of Fallot
- C Ventricular septal defect with polyvalvular disease (VSD + dysplastic valves) ✓
- D Coarctation of the aorta
Explanation
Trisomy 18 (Edwards syndrome) is associated with complex cardiac defects in over 90% of cases. The most characteristic combination is ventricular septal defect along with polyvalvular disease (dysplastic, thickened cardiac valves — particularly aortic and pulmonary), which is highly distinctive of trisomy 18. AVSD (endocardial cushion defect) is the classic defect of trisomy 21 (Down syndrome). Tetralogy of Fallot has weaker chromosomal association. Coarctation of the aorta is associated with Turner syndrome (45,X). The polyvalvular abnormality in trisomy 18 reflects a specific developmental pathway disruption different from other trisomies.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
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Written and medically reviewed by the StethoPrep medical team.