Familial recurrence of nonsyndromic interrupted aortic arch and truncus arteriosus with atrioventricular canal

Background: Multifactorial inheritance is probably involved in most cases of nonsyndromic conotruncal heart defects (CHDs), but Mendelian transmission is often suspected. Results: We report on a family with recurrence of nonsyndromic CTHD in two double first cousins; i.e., two brothers married two sisters. One of the cousins (case 1) had interrupted aortic arch (IAA) type B, while the other one (case 2) had truncus arteriosus (TA) with atrioventricular canal defect (AVCD). Conclusions: Our family further supports monogenic inheritance of CTHDs. In addition, the presence of TA associated with AVCD in one of the patients confirms the higher occurrence of CTHD in families with complex TA. The absence of 22q11 microdeletion [del22q11] in our patients, as in several literature reports of familial CTHDs, supports the existence of genes different to those located on chromosome 22q11 which could be implicated in the pathogenesis of CTHDs. (C) 2000 Wiley-Liss, Inc.