Congenital absence of the left pericardium and diaphragmatic defect in sibs.

Congenital absence of the left pericardium (allowing communication between pericardial and pleural cavities) is a rare developmental defect that results from faulty partitioning of the pleuropericardic cavity during the 5th week of development. It occurs sporadically in most instances, and may be associated with other malformations of the thoracic viscera. We report here two sibs born to consanguineous parents with absent left fibrous pericardium and developmental defects of the septum transversum: left posterolateral diaphragmatic hernia in one child, left diaphragmatic eventration in the other sib. This appears to be the first familial report of this rare association.