Autosomal dominant atrial septal defect of ostium secundum type. Report of three families.

The authors report on three Sicilian families with 17 individuals (10 females and 7 males) in successive generations affected by atrial septal defect of ostium secundum type (S-ASD) without conduction defect. The anomaly was inherited as an autosomal dominant trait. Cytoplasmic inheritance could be excluded, the anomaly being transmitted also by fathers. Familial S-ASD is probably more frequent than commonly reported since cardiological examination of the relatives is not routinely performed in every case of apparently sporadic ASD.