This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hemolytic Anemias: Basic concepts and classification, Subject name: Pathology
[{'content': "CD 59 deficiency leads to:- \nSelect and explain. \nA. Chediak Higashi disease, B. TTP, C. PNH, D. Burkitt's Lymphoma", 'role': 'user'}, {'content': 'Answer: C \nExplanation: PNH: - D/t acquired mutations in phosphatidyl inositol glycan complementation group A gene (PIGA), an enzyme essential for synthesis of ceain membrane-associated complement regulatory proteins. - Blood cells are deficient in three GPI-linked proteins that regulate complement activity: Decay accelerating factor, or CD55; Membrane inhibitor of reactive lysis, or CD59; C8 binding protein. - It results in complement activation abnormally resulting in - destruction of RBC, WBC, platelets - Pancytopenia - PNH is diagnosed by Flaer flow cytometry, which provides a sensitive means for detecting red cells that are deficient in GPI-linked proteins such as CD59.', 'role': 'assistant'}]