Dizygotic twins concordant for truncus arteriosus.

Persistent truncus arteriosus (TA) is an uncommon congenital cardiovascular malformation, which comprises between 0.4% and 4% of all congenital heart defects. Occurrence of TA in siblings has been reported infrequently. Twins concordant for isolated TA appear to have been reported only once previously. In this paper, we describe dizygotic twin females who were concordant for isolated TA.