Familial interruption of the aortic arch.

Interruption of the aortic arch (IAA) is an important congenital cardiac malformation occurring in 1.4% of cases with a congenital cardiac malformation. Only two reports have described IAA in siblings, each with type B and an anomalous right subclavian artery. We report the occurrence of IAA type B with an anomalous right subclavian artery in two siblings and their half-sibling, each of whom had additional conotruncal cardiac malformations. Recent evidence suggests that conotruncal cardiac malformations, including IAA type B, are related to abnormalities of neural crest cell migration. Thus, the family reported herein may manifest a syndrome related to alterations in mesenchymal tissue/neural crest cell migration.