This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Syndrome which is characterized by 2X chromosomes and 1Y chromosome is: 
Select and explain. 
A. Kleinfelter syndrome, B. Down syndrome, C. Turner syndrome, D. Marfan syndrome
A: Kleinfelter syndrome
Answer: A: Kleinfelter syndrome 
Explanation: Klinefelter’s syndrome is associated with an extra X chromosome (47, XXY).
Mohan H. Textbook of pathology. Jaypee Brothers Medical Publishers; 2015. Edition 7. Page 198