A 3-week-old infant presents with tachypnoea, recurrent chest infections, and bounding peripheral pulses. Examination shows a single second heart sound and a harsh systolic murmur along the left sternal border with a diastolic component. Chest radiograph shows cardiomegaly with increased pulmonary vascular markings. Which associated finding is MOST likely?

• A Absent thymus with hypocalcaemia due to 22q11.2 deletion ✓
• B Supravalvular mitral ring with Shone complex
• C Bilateral superior vena cava with asplenia
• D Jervell and Lange-Nielsen prolongation of QT interval

Explanation

The bounding pulses plus a single S2 and a to-and-fro murmur in an infant with cardiac failure indicate persistent truncus arteriosus, where one arterial trunk arises overriding a VSD and gives off both coronaries, pulmonaries, and the aorta. About one third of cases have 22q11.2 deletion causing thymic aplasia and hypocalcaemia (DiGeorge spectrum). Asplenia syndromes associate with complex venous anomalies, not isolated truncus.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.