Interrupted aortic arch: An epidemiologic study

Background: interruption of the aortic arch (IAA) is a rare but severe anom aly associated with major intracardiac defects and with multisystem noncard iac malformations, recently linked to chromosome deletion of 22q11.2. Methods: The Baltimore-Washington Infant Study (1981-1989), a population-ba sed epidemiologic study of cardiovascular malformations, evaluated 53 infan ts with IAA in comparison with 3,572 controls. Risk factors for the anatomi c subtypes were evaluated in 14 cases of]AA type A and 32 cases of IAA type B, but no molecular genetic tests were available. The distribution of asso ciated cardiac defects was similar for both types. Results: DiGeorge syndrome (DGS) occurred more frequently in IAA type B. Ca se-control comparisons demonstrated that infants in both groups were growth retarded at birth. A family history of noncardiac defects occurred only in IAA type 8 cases and included relatives with cleft lip and/or cleft palate . Candidate risk factors were associated only in type B cases and differed for those with (n = 10) and for those without (n = 19) DGS: a family histor y of noncardiac defects [odds ratio [OR] = 7.2, 95% confidence interval [CI ] = 1.5-39.2) and maternal use of aspirin during the critical period (OR = 4.8, 95% CI = 1.3-25.4) occurred with DGS, while previous stillbirth (OR = 9.4, 95% CI = 1.3-53.1), bleeding during pregnancy (OR = 3.7, 95% CI = 1.4- 11.4), and maternal exposure to arts/crafts paints (OR = 4.8, 95% CI = 1.3- 17.4) were associated in those without DGS. Conclusions: These findings confirm the heterogeneity of IAA and of the typ e 8 subtype. Risk factors specific for cases with DGS may open a window to further investigations of the etiology of IAA and of the associated molecul ar genetic abnormalities. (C) 2000 Wiley-Liss, Inc.