This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Specific Cytogenetic Disorders, Subject name: Pathology
Barr body is not seen in: 
Select and explain. 
A. Klinefelter syndrome, B. Turner syndrome, C. Normal female, D. XXX syndrome
B: Turner syndrome
Answer: B: Turner syndrome 
Explanation: Barr body, or X chromatin Inactive X can be seen in the interphase nucleus as a darkly staining small mass in contact with the nuclear membrane known as the. Number of Barr bodies = number of X chromosome -1 , Turner syndrome patients, number of Barr body = 1-1=0.