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: Pediatrics
All the following are causes of hematuria in a child except: 
Select and explain. 
A. PCKD, B. Porphyria, C. Renal vein thrombosis, D. Idiopathic hypercalciuria
B: Porphyria
Answer: B: Porphyria 
Explanation: Cause of Persistent microscopic hematuria include idiopathic hypercalciuria. Porphyria does not produce hematuria. Ref: Nelson, 18th Edition, Page 2169