A neonate with dysmorphic features including upward-slanting palpebral fissures, a single palmar crease, sandal-gap deformity, hypotonia, and a murmur of VSD is evaluated. Karyotype is 47, XY, +21. What is the MOST common cardiac defect associated with this condition?

• A Ventricular septal defect alone
• B Tetralogy of Fallot
• C Transposition of great arteries
• D Atrioventricular septal defect (AVSD) ✓

Explanation

Down syndrome (trisomy 21) is the most common chromosomal abnormality, and atrioventricular septal defect (AVSD, also called endocardial cushion defect) is the MOST common associated cardiac defect, occurring in about 40% of cases. Complete AVSD involves both ASD (primum type) and VSD with a common AV valve. Congenital heart disease occurs in 40-50% of Down syndrome children and is the leading cause of early mortality in this group.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.