Assessment of cardiovascular findings in children with chromosomal anomalies or single-gene variants

The demographic data, growth SDS values, and baseline–follow-up echocardiographic findings of patients diagnosed with Down syndrome, Turner syndrome, Noonan syndrome, DiGeorge syndrome, Marfan syndrome, Williams syndrome, Tuberous sclerosis and Duchenne muscular dystrophy (DMD) were retrospectively analyzed in the Pediatric Cardiology Clinic of Trakya University between January 2018 and January 2024. General (Neyzi) and syndrome-specific growth references (Zemel, Rongen-Westerlaken, Malaquias) and aortic measurement Z-scores (Cantinotti and Quezada) were used. Chi-square and appropriate parametric/non-parametric tests were applied according to variable type. In patients with Down syndrome, the prevalence of congenital heart disease was high, most commonly atrioventricular septal defect (AVSD), followed by mitral regurgitation, ventricular septal defect (VSD), and atrial septal defect (ASD). The presence of AVSD was associated with a significantly higher progression of mitral regurgitation. More than half of Turner syndrome patients had congenital heart disease, most frequently bicuspid aortic valve, followed by coarctation and ascending aortic dilatation; follow-up Z-scores increased significantly in all segments, with Cantinotti values higher than Quezada. In Noonan syndrome, cardiac involvement (76.9%) was mainly pulmonary valve stenosis, followed by hypertrophic cardiomyopathy and ASD; mild-to-moderate pulmonary valve stenosis remained stable, while pulmonary regurgitation slightly increased. DiGeorge syndrome patients (77.2%) predominantly had conotruncal defects. In Marfan syndrome, mitral valve prolapse and mitral regurgitation predominated, with less frequent aortic dilatation. Williams syndrome cases mainly showed supravalvular aortic and peripheral pulmonary stenosis with low progression rates. Multiple cardiac rhabdomyomas in Tuberous sclerosis tended to regress spontaneously, whereas DMD cases were largely normal in childhood, showing dilation during adolescence. General growth references exaggerated height and weight deficits compared to syndrome-specific charts. Syndrome-based growth and cardiac references significantly refine clinical interpretation. AVSD in Down syndrome, aortopathy in Turner syndrome, right ventricular outflow tract abnormalities in Noonan syndrome, and conotruncal defects in DiGeorge syndrome require close longitudinal follow-up. Serial echocardiography can reliably detect prognostic changes even during childhood.