Familial atrial septal defect with prolonged atrioventricular conduction.

This report describes a family with frequent recurrence of congenital heart disease in multiple generations. Eight members had atrial septal defect (ASD) of the fossa ovalis type and seven members had other forms of congenital heart disease. One branch of the pedigree showed a predominance of ASD with prolonged atrioventricular (A-V) conduction and initially suggested an autosomal dominant gene effect. A variety of other forms of congenital heart disease were found in several first degree relatives of those with ASD as well as in more distant relatives. The variability of congenital heart disease in this pedigree is compatible with the polygenic mode of inheritance. Definition of the inheritability of congenital heart disease in a specific family has important consequences in the determination of the recurrence risks for all family members.