[Secundum atrial septal defect in two families]

Two families having secundum atrial septal defect (ASD) were reported. In one family, a 31-year-old male and his 60-year-old mother had secundum ASD without PR prolongation. His 38-year-old brother was diagnosed as having ASD. His grandmother, who had died at the age of 51, was suspected of having congenital heart disease. From early childhood she was noticed to have heart murmur. It was suspected that this was a case of familial ASD without PR prolongation, because it was consistent with the dominant trait of the defect. In the other family, a 16-year-old female had secundum ASD and her 18-year-old brother was also suspected of having ASD. Her 25-year-old brother had been operated on for tetralogy of Fallot, and her sister had died of an unknown congenital heart disease. All of these family members had mental retardation. Her 22-year-old brother was suspected of having a congenital heart disease, because of heart murmur from his early childhood. The parents, who were blood relations (cousins), had neither heart disease nor mental retardation. The children of this family were considered to be cases of congenital heart disease with ASD, associated with mental retardation. It was also suspected that the cause of the defect was a deleterious autosomal recessive gene.