RESUMEN
The occurrence of several cases of ASD in the same family is rare. Familial forms of ASD are characterised by the high incidence of associated cardiac lesions in affected patients or in the family, by the frequency of atrioventricular block with prolongation of the PR interval and by the presence of a large defect in the interatrial septum. The condition is thought to be transmitted in an autosomal dominant manner. The authors report the case of a family in which 7 cases of ASD were found, 6 of which were repaired surgically. There were no associated cardiac or extracardiac malformations; AV conduction was normal in 4 of the 6 operated cases--the defects were all large. The study of the genealogical tree with examination of most members of the family suggests autosomal dominant transmission of the condition.