An 8-week-old infant presents to the pediatrician for a well-baby checkup. Physical exam reveals a murmur, and an echocardiogram confirms a ventricular septal defect. Which genetic disorder is likely to accompany this diagnosis?

a. Huntington disease
b. Color blindness
c. Down syndrome
d. Hemophilia

ANS: C
Down syndrome is the genetic factor that would most likely accompany the diagnosis of a con-genital heart defect. Neither Huntington disease, color blindness, nor hemophilia is a genetic dis-order that would most likely accompany a diagnosis of congenital heart defect.