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: Microbiology
Karyotyping can be used to diagnose which of the following disease? 
Select and explain. 
A. Klinefelter’s syndrome, B. Multiple myeloma, C. Niemann-Pick disease, D. Pemphigus
A: Klinefelter’s syndrome
Answer: A: Klinefelter’s syndrome 
Explanation: The only disease listed that is related to an abnormal number of chromosomes is Klinefelter’s syndrome. This disease is characterized by two or more X chromosomes and one or more Y chromosome. Typically, those affected have 47 chromosomes with a karyotype of XXY.