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
Acquired mutations in PIGA  gene gives rise to: 
Select and explain. 
A. Paroxysmal Nocturnal Hemoglobinuria, B. Hereditary Spherocytosis, C. Isoimmune hemolytic anemia, D. Fanconi’s anemia
A: Paroxysmal Nocturnal Hemoglobinuria
Answer: A: Paroxysmal Nocturnal Hemoglobinuria 
Explanation: Paroxysmal nocturnal hemoglobinuria (PNH) is a hemolytic anemia that stems from acquired mutations in PIGA, a gene required for the synthesis of phosphatidylinositol glycan (PIG), which serves as a membrane anchor for many proteins. Because PIGA is X-linked, normal cells have only one active PIGA gene, a mutation of which is sufficient to cause PIGA deficiency.
Robin’s Textbook of pathology 10th ed Page 450