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
Which of the following is the only hemolytic anaemia caused by acquired intrinsic defect in the cell membrane: 
Select and explain. 
A. Sickle cell anaemia, B. Thalassemia, C. PNH, D. None of the above
C: PNH
Answer: C: PNH 
Explanation: PNH is the only hemolytic anemia caused by an acquired intrinsic defect in the cell membrane. 
The stem cells of the bone marrow acquire mutations in Phosphatidyl inositol glycan A (PIGA) gene. 
The triad of hemolysis, pancytopenia and thrombosis is unique to PNH. 
Thrombosis is the leading cause of disease related death in PNH.