Q. A 9-year-old boy is brought to the physician’s office by his mother for numbness in both hands for the past 2 years. The mother says that initially the boy was taken to the psychiatrist for inattentive and asocial behavior. But as he also has numbness, he was referred to the physician. His medical history shows that he was operated on for a ventricular septal defect at the age of 6 years. His birth history and family history are insignificant. His temperature is 98.6°F (37°C), pulse is 90/min, blood pressure is 110/80 mmHg, and respirations are 14/min. Physical examination shows mild facial dysmorphism with a prominent nose with a bulbous tip, small mouth and eyes, ocular hypertelorism, and a long face. A surgical scar is noted on his chest. Lab investigations are shown below. What is the chromosomal abnormality that is most likely associated with this constellation of signs and symptoms?