Any ventricular septal defect in which the cause of the disease is a mutation in the NKX2-5 gene. The disease is ventricular septal defect 3 (MONDO_0013749, a Monarch Disease Ontology identifier). Also known as: NKX2-5 ventricular septal defect (disease), ventricular septal defect (disease) caused by mutation in NKX2-5, ventricular septal defect type 3.