Clinical characteristics and outcomes of syndromic children with ventricular septal defect: A single-center study

Objective: Ventricular septal defect (VSD) is the most common congenital heart defect and frequently accompanies genetic syndromes.This study aimed to evaluate the demographic characteristics, VSD morphology, associated syndromes, and clinical outcomes ofsyndromic children with isolated VSD.Patients and Methods: This retrospective single-center study included 88 syndromic children with isolated VSD followed at a tertiarypediatric cardiology center between 1991 and 2024 (8.8% of all isolated VSD cases). Clinical, echocardiographic and genetic dataand VSD outcomes were reviewed. Patients with suspected genetic syndromes underwent stepwise clinical and molecular geneticevaluation.Results: Down syndrome was the most common diagnosis (48.9%), followed by unclassified syndromic conditions (18.2%) and raregenetic syndromes (20.5%). Muscular VSD was the predominant subtype, and small defects were the most common. Pulmonaryhypertension (PHT) was present in 20.5%. Surgical or transcatheter intervention was required in 20.5%, while spontaneous VSDclosure occurred in 27.3% during follow-up.Conclusion: Syndromic children with isolated VSD represent a heterogeneous population with diverse genetic diagnoses and variableoutcomes; Down syndrome was the predominant syndrome. VSD anatomy and defect size were among the main determinantsof spontaneous closure, whereas PHT was an important and often multifactorial concern. These findings may facilitate clinicalsurveillance and management.