BACKGROUND:

Congenital cardiovascular malformations are a major cause of infant mortality in the United States. In 1985, six defects -- hypoplastic left heart, tetralogy of Fallot, truncus arteriosus, transposition of the great arteries, endocardial cushion defect, and ventricular septal defect -- were among the fifteen most frequent causes of premature death due to congenital malformations, accounting for 109,063 years of life lost. This loss of productive life continues in spite of major advances in medical and surgical treatment of congenital cardiovascular malformations. Even as successful treatment modalities are developed, the survival to reproductive years without improved understanding of genetic risks produces additional unanswered questions.

DESIGN NARRATIVE:

Clinical assessment of cases and controls included medical history, pedigree construction, complete evaluation by a pediatric cardiologist, and two-dimensional and Doppler echocardiography. First degree relatives of cases and controls underwent clinical-echocardiographic evaluation also. The distribution of cardiac defects for all pedigrees within and among the proband group was delineated. The frequencies of heart defects were compared within and among pedigrees of cases and controls. Regressive logistic models of genetic determinants for the malformations were tested. The three participating clinical centers included University of Maryland at Baltimore, the Johns Hopkins Hospital, and the University of Rochester in Rochester, New York.