Total anomalous pulmonary venous connection in siblings. Report on three families.

Three pairs of siblings with total anomalous pulmonary venous connection (TAPVC) are reported. The types of the anomalous venous return (supra- or infracardial connections) varied within the families indicating that genetic regulation deals with the left atrial connection to the intrapulmonary veins. Having failed to establish this connection the intrapulmonary veins can attach themselves to any adjacent venous structure; hence the variety of connections at birth. Our observations also indicate the possibility that specific genetic mechanisms operate in at least some families. Since signs, such as murmurs and cardiomegaly typical of a cardiac anomaly, are not always present in TAPVC, special attention should be paid to any neonatal abnormality in siblings of known cases with TAPVC.