A neonate presents with mild cyanosis, bounding peripheral pulses, a single loud second heart sound, and a wide pulse pressure. Echocardiography shows a single large arterial trunk overriding the ventricular septum, originating from both ventricles, with a main pulmonary artery arising directly from the trunk. Which genetic abnormality is most characteristically associated with this lesion?

• A Trisomy 21
• B 45,X monosomy
• C Mutation in the JAG1 gene on chromosome 20p12
• D Microdeletion of chromosome 22q11.2 ✓

Explanation

Persistent truncus arteriosus results from failure of septation of the embryonic truncus arteriosus, and neural crest developmental fields are implicated. It is strongly associated with the 22q11.2 microdeletion causing DiGeorge syndrome, so affected infants should be assessed for thymic hypoplasia, hypocalcaemia, and immune deficiency before thymus-containing blood products are given. JAG1 mutations cause Alagille syndrome, which features peripheral pulmonary stenosis instead.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.