A patient with a history of recurrent venous thrombosis is found to have a mutation in the MTHFR gene. What is the underlying mechanism contributing to the increased risk of thrombosis?

A Increased homocysteine levels leading to endothelial damage ✓
B Decreased protein C levels due to impaired transcription
C Impaired antithrombin activity due to altered binding affinity
D Enhanced factor V activation due to altered gene expression

Explanation

The MTHFR gene mutation leads to increased homocysteine levels, which can cause endothelial damage and increase the risk of venous thrombosis.

Source

New England Journal of Medicine, 2019
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Hard MEDICAL Confidence: medium