Case Report: Prenatal clues and postnatal evolution: a case of williams syndrome diagnosed following progressive cardiovascular phenotypes.

Background: Williams syndrome (WS) is a rare genetic disorder often missed prenatally due to nonspecific presentations. Case presentation: We describe an infant with Williams syndrome diagnosed after progressive cardiovascular changes during infancy. Prenatal ultrasonography showed fetal growth restriction, persistent left superior vena cava (PLSVC), left-right cardiac chamber disproportion (LRCCD), and suspected coarctation of the aorta (CoA). Early postnatal echocardiography revealed mild aortic isthmus hypoplasia without definite supravalvular aortic or pulmonary arterial stenosis. Serial follow-up subsequently demonstrated supravalvular aortic stenosis (SVAS) and right pulmonary artery stenosis by 7 months of age, and chromosomal microarray analysis (CMA) confirmed a 1.42 Mb deletion at 7q11.23. At 5 years and 3 months of age, the child remained clinically stable, with stable SVAS and near resolution of pulmonary arterial stenosis. A retrospective review of nine fetuses with prenatally confirmed 7q11.23 microdeletion showed that prenatal cardiovascular abnormalities were present in 6 cases, mainly involving the aortic and pulmonary arterial systems, often with extracardiac findings such as renal anomalies and fetal growth restriction (FGR). Conclusion: WS may show dynamic cardiovascular evolution from nonspecific prenatal or neonatal findings to characteristic vascular lesions during infancy. Fetal cardiovascular abnormalities combined with FGR or other extracardiac anomalies should raise suspicion for WS and prompt consideration of CMA. Serial postnatal echocardiography may help clarify prenatal clues and facilitate earlier diagnosis and management.