<prompt> Most common type of inherited disease of hypercoagulobility is?Protein C deficiencyLeiden mutationDICAntithrombin III deficiency  <response>: Ans. is b i.e., Leiden mutation Of the inherited causes of hypercoagulability, mutation in factor V gene is the most common. Factor V mutations called the leiden mutation causes subsitution of arginine residue at position 506 by glutamine. This mutation makes factor V resistant to cleavage by protein C normally protein C is one of the factor that regulates coagulation by inactivating factor V VIII. This results in unchecked coagulation. 