Ultrasonography at 18 weeks gestation reveals a male fetus with an endocardial cushion defect (atrio-ventricular canal defect). Other abnormalities include increased nuchal thickening and a "double bubble" sign suggesting duodenal atresia. Which of the following conditions is most likely to have contributed to this set of findings:
A Maternal use of phentermine-dexfenfluramine
B Marfan syndrome
C Maternal folate deficiency
D Trisomy 21
E Congenital syphilis
(D) CORRECT. This spectrum of findings is typical for Down syndrome, with a 47, XY, +21 karyotype. The most common congenital heart diseases with Down syndrome involve the endocardial cushion.
M.D., PGY-3 Internal Medicine