Heterotaxy Syndrome With Right Isomerism and Interrupted Inferior Vena Cava: A Case Report and Literature Review.

Heterotaxy syndrome (HS) occurs in developing embryos due to an inability to establish the normal anatomy, which manifests as abnormal symmetry and malposition of the thoracoabdominal viscera and vasculature, including cardiac and extracardiac anomalies. It is classified as right or left atrial isomerism. This classification depends on the atrial appendage morphology and the extracardiac defect associated with it. Right isomerism usually presents with right atrial appendages (RAA), asplenia, total anomalous pulmonary venous return, and severe pulmonary stenosis. In contrast, left isomerism usually presents with left atrial appendages, polysplenia, and an interrupted inferior vena cava (IVC). The interrupted IVC feature has never been reported with the right isomerism. Diagnosis of HS may take place prenatally or a few days postnatally due to the severe cardiac defect, whereas a left isomerism diagnosis may be delayed until adulthood. Despite the popularity of the HS classification, we reported a rare presentation of an interrupted IVC, dextrocardia, a right-sided aortic arch, and a total anomalous pulmonary venous return, which occurred along with the right isomerism major components (asplenia syndrome).