Congenital extracardiac venous system anomaly in two siblings with normal karyotype and increased nuchal translucency thickness: a case report

Previous studies have reported that congenital heart diseases (CHDs) develop in patients with genetic and environmental predisposition. Compared to CHDs, the significance of hereditary factors in the pathogenesis of congenital venous system anomalies remains unclear. Additionally, reports describing the pathogenic relationship between venous system anomalies and increased nuchal translucency (NT) are few. We report sibling recurrence of congenital venous system anomalies. In the prenatal periods of both siblings, increased NT without aneuploidy was confirmed. In the first sibling, the absence of ductus venosus (ADV) and umbilical vein-coronary sinus anastomosis was detected using prenatal ultrasonography. In the second sibling, abnormality of the pulmonary vein was suspected prenatally, leading to a final diagnosis of infracardiac total anomalous pulmonary venous return (TAPVR). This is the first report of extracardiac venous anomaly-associated recurrence of increased NT among siblings. We conclude that a hereditary factor may be responsible for the development of ADV and TAPVR.