Risk of Down syndrome in duodenal atresia and atrioventricular septal defect: Is there an ethnic difference?

Purpose: Duodenal atresia (DA) and atrioventricular septal defect (AVSD) are well known ultrasonographic ἀndings associ-ated with Down syndrome. The risk of Down syndrome in fetuses with these anomalies has been reported as 30% to 40%. However, on the basis of our clinical experience, the risk of Down syndrome of DA may be lower in Korean population. To clarify this issue, we compared the risk of Down syndrome between cases with DA and AVSD.Materials and Methods: The study population consisted of neonates who were conἀrmed as DA or AVSD by postnatal diag-nosis. Postnatal diagnosis was made by surgery, postnatal echocardiography, or autopsy. Medical record was reviewed retro-spectively. Results: A total of 213 neonates with DA or AVSD were included: 67 cases with DA and 146 cases with AVSD. The risk of Down syndrome was 4.5% (3/67) in DA vs. 29.5% (43/146) in AVSD. When conἀning analysis to those whose karyotyping were not performed during antenatal period, the risk of Down syndrome were 7.9% (3/38) in DA and 35.4% (35/99) in AVSD.Conclusion: The risk of Down syndrome in cases with DA was much lower in Korean population than previously reported risk in the literature. The signiἀcance of some antenatal sonographic markers for Down syndrome may be different according to ethnicity.