A 2-day-old neonate is admitted to the neonatal intensive care unit after being noted to have a heart murmur and dysmorphic facial features. On further evaluation, the infant is found to have a conotruncal cardiac defect, cleft palate, and hypocalcemia. The neonate also has a history of recurrent infections. These findings raise concern for a genetic syndrome associated with aberrant development of certain embryologic structures. Which embryologic abnormality is most commonly responsible for the constellation of findings seen in this neonate, including conotruncal cardiac defects, abnormal facies, thymic hypoplasia, cleft palate, and hypocalcemia (commonly known as CATCH 22)?
