What amino acid substitution occurs in the Factor 5 Leiden mutation?

The Factor 5 Leiden mutation results from a specific amino acid substitution in the Factor V protein, where arginine is replaced by glutamine at position 506. This mutation impairs the protein's ability to be inactivated by activated protein C, leading to an increased risk of thrombosis. The substitution of arginine, which is a positively charged amino acid, with glutamine, which is neutral, alters the protein's structure and function dramatically.

This particular change at the molecular level is crucial because it specifically affects the coagulation cascade, enhancing the likelihood of clot formation. Understanding this specific substitution is essential in the context of thrombophilia and helps in diagnosing and managing patients with increased thrombotic risk due to this mutation. The details of the substitution underscore why this mutation is significant in clinical practice related to blood coagulation disorders.