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
Leiden mutation is 
Select and explain. 
A. Non sense mutation, B. Mis-sense mutation, C. Frame shift mutation, D. Tri nucleotide repeat mutation
B: Mis-sense mutation
Answer: B: Mis-sense mutation 
Explanation: Ans. is 'b' i.e., Mis-sense mutation Factor V Leiden (FVL) mutation is a mis-sense type of point mutation in the gene for clotting factor V. As a missense substitution of base G to base A, it changes the protein's amino acid from arginine to glutamine.It has autosomal dominant inheritance and is the most common cause of inherited thrombophilia.Factor V is one of the essential clotting factors in the coagulation cascade.FVL mutation causes activated protein C resistance, hence leading to the hypercoagulable state.It is associated with increased risk of DVT 6, recurrent miscarriages