Familial truncus arteriosus: a possible autosomal-recessive trait.

Truncus arteriosus is a relatively uncommon congenital malformation. It accounts for approximately 1% of congenital heart diseases. The defect occurs sporadically but 22q11 deletion is frequently noted in such patients with conotruncal defects. We studied six cases of TA in four closely related families. Analysis of karyotypes in these cases was normal. Family 1 has one affected male infant who was born in 1998. Family 2 has two affected children (one male and one female) who were born in 1989 and 1995, respectively. They have four other normal children. Family 3 has two affected children (one male and one female) who were born in 1981 and 1984, respectively. They have three other normal children. Family 4 has one affected male born in 1998 and another healthy child. All parents of all affected children are double cousins. The data in this study are compatible with an autosomal-recessive inheritance, but multifactorial inheritance may also play a role.