A newborn has holoprosencephaly, midline cleft lip and palate, microcephaly, and postaxial polydactyly. Karyotype shows 47,XX,+13. Which cardiac defect is most commonly associated with this chromosomal abnormality?

• A Transposition of the great arteries
• B Atrioventricular septal defect
• C Tetralogy of Fallot
• D Ventricular septal defect ✓

Explanation

Trisomy 13 (Patau syndrome) classically presents with midline defects including holoprosencephaly, cleft lip and palate, microphthalmia, and postaxial polydactyly. Ventricular septal defect is the most common cardiac anomaly in trisomy 13. Atrioventricular septal defect is strongly associated with trisomy 21 (Down syndrome), not trisomy 13. Tetralogy of Fallot and transposition occur but are not the predominant cardiac defects in Patau syndrome.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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