This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pathology
Mutation in protein associated with restrictive cardiomyopathy? 
Select and explain. 
A. Myosin regulatory proteins, B. Myosin binding protein-C, C. Troponin I, D. Tropomyosin
C: Troponin I
Answer: C: Troponin I 
Explanation: Ans. is 'c' i.e. Troponin I * RCM-associated mutations have been reported in four genes that encode key sarcomeric proteins/myofilaments1. MYH7 gene - b-Myosin heavy chain2. TNNI3 gene - Cardiac troponin I type 33. TNNT2 gene- Cardiac troponin T type 24. ACTC gene - a- actin* Mutations in the TNNI3 gene & MYH7 gene are the major causes of this condition.