Occurrence of congenital heart defects in siblings of patients with univentricular heart and tricuspid atresia.

Because of the rarity of univentricular heart and tricuspid atresia, no study of a large number of patients has been made to determine the empiric occurrence risks of a congenital heart defect in their siblings. A retrospective chart review was performed of 223 patients with univentricular heart and 113 with classic tricuspid atresia evaluated from 1982 to 1987. Thirty-four patients with univentricular heart and 17 with tricuspid atresia had no siblings and were excluded. Eleven of the total 388 siblings (2.8%) of the 189 patients with univentricular heart had a congenital heart defect. Of the siblings born after the index case of univentricular heart, 7 of 169 (4.1%) had a congenital heart defect. Two of the 210 siblings (1.0%) of the 96 patients with tricuspid atresia had a congenital heart defect. The patients with univentricular heart were subdivided into 4 groups: (1) double-inlet left ventricle; (2) complex univentricular heart with single or common inlet, or with a ventricle of common or right ventricular morphology; (3) complex univentricular heart with asplenia; and (4) complex univentricular heart with polysplenia. One of the 202 siblings (0.5%) of the 102 patients with double-inlet left ventricle had a congenital heart defect, compared with 7 of the 140 siblings (5.0%) of the 69 patients with complex univentricular heart, 1 of the 29 siblings (3.4%) of the 14 patients with complex univentricular heart and asplenia, and 2 of the 7 siblings (28.6%) of the 4 patients with complex univentricular heart and polysplenia.(ABSTRACT TRUNCATED AT 250 WORDS)