A newborn is noted to have a single palmar crease, upslanting palpebral fissures, epicanthal folds, protruding tongue, and hypotonia. Cardiac examination reveals a grade 3/6 systolic murmur. Karyotype confirms trisomy 21. Which cardiac lesion is the MOST commonly associated with Down syndrome?

• A Tetralogy of Fallot
• B Transposition of the great arteries
• C Atrioventricular septal defect (AVSD / endocardial cushion defect) ✓
• D Pulmonary stenosis

Explanation

Atrioventricular septal defect (AVSD), also called endocardial cushion defect or complete AV canal, is the most common congenital heart defect in Down syndrome, occurring in approximately 40–50% of Down syndrome patients with CHD. It involves both ASD (primum type) and VSD along with abnormal AV valves. VSD (perimembranous) is the most common individual lesion overall in Down syndrome, but AVSD is the pathognomonic association.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.