A 5-year-old child with intellectual disability (IQ 45) and characteristic facial features (upslanting palpebral fissures, epicanthal folds, single palmar crease, flattened occiput, and protruding tongue) is evaluated. Karyotype shows 47,XX +21. Which cardiac lesion is MOST commonly associated?

• A Atrioventricular septal defect / endocardial cushion defect (AVSD) ✓
• B Ventricular septal defect (VSD)
• C Atrial septal defect (ASD)
• D Tetralogy of Fallot (TOF)

Explanation

Down syndrome (trisomy 21) is associated with congenital heart disease in ~40–50% of cases. The MOST characteristic and common lesion is the atrioventricular septal defect (AVSD/endocardial cushion defect), accounting for approximately 40–45% of the CHD in Down syndrome. VSD is also common (~30–35%) but AVSD is the most characteristic lesion. The complete form of AVSD includes ASD primum, VSD, and a common AV valve. Early surgical correction is essential before the development of pulmonary vascular disease. TOF occurs less commonly (~5%) in Down syndrome.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.