title: Interrupted aortic arch: an epidemiologic study.
abstract: BACKGROUND
  Interruption of the aortic arch (IAA) is a rare but severe anomaly associated with major intracardiac defects and with multisystem noncardiac malformations, recently linked to chromosome deletion of 22q11.2.
  
  
  METHODS
  The Baltimore-Washington Infant Study (1981-1989), a population-based epidemiologic study of cardiovascular malformations, evaluated 53 infants with IAA in comparison with 3,572 controls. Risk factors for the anatomic subtypes were evaluated in 14 cases of IAA type A and 32 cases of IAA type B, but no molecular genetic tests were available. The distribution of associated cardiac defects was similar for both types.
  
  
  RESULTS
  DiGeorge syndrome (DGS) occurred more frequently in IAA type B. Case-control comparisons demonstrated that infants in both groups were growth retarded at birth. A family history of noncardiac defects occurred only in IAA type B 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 history 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 type B subtype. Risk factors specific for cases with DGS may open a window to further investigations of the etiology of IAA and of the associated molecular genetic abnormalities.
authors.affiliation: Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. cloffredo@som.umaryland.edu
authors.forename: C A
authors.initials: CA
authors.lastname: Loffredo
authors.forename: C
authors.initials: C
authors.lastname: Ferencz
authors.forename: P D
authors.initials: PD
authors.lastname: Wilson
authors.forename: I W
authors.initials: IW
authors.lastname: Lurie
mesh_terms: D000015:Abnormalities, Multiple / Q000453:epidemiology; D001013:Aorta, Thoracic / Q000002:abnormalities*; D016022:Case-Control Studies; D002892:Chromosomes, Human, Pair 22; D002971:Cleft Lip / Q000453:epidemiology; D002972:Cleft Palate / Q000453:epidemiology; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000235:genetics; D004062:DiGeorge Syndrome / Q000453:epidemiology; D005260:Female; D006343:Heart Septal Defects / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016013:Likelihood Functions; D008297:Male; D012307:Risk Factors