Atrial septal defect in three generations.

Congenital heart disease occurs in two or more members of a family more often than can be accounted for by chance. Campbell (1959) found the condition to occur less commonly in parent and child than in sibs, and it occurs much less frequently in three generations, but he had two such families in his series: in one the girl, her mother, and grandmother all had atrial septal defects; in the other the boy and mother had aortic stenosis and the grandfather was said to have had a similar heart condition but had not been examined.