This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pediatrics
The coagulation profile in a 13 year old girl with menorrhagia having von Willebrand&;s disease is 
Select and explain. 
A. Isolated prolonged PTT with a normal PT, B. Isolated prolonged PT with a normal PTT, C. Prolongation of both PT and PTT, D. Prolongation of thrombin time
A: Isolated prolonged PTT with a normal PT
Answer: A: Isolated prolonged PTT with a normal PT 
Explanation: In vonwillebrand disease aPTT will be prolonged and PT will be normal. Reference: GHAI Essential pediatrics, 8th edition