Cleveland Clinic Journal of MedicineIs the MTHFR Gene Mutation Associated with Thrombosis?

Clinicians should educate patients with MTHFR polymorphisms about the lack of evidence for association with thrombotic risk and focus on addressing modifiable thrombotic risk factors.

The methylene tetrahydrofolate reductase (MTHFR) gene, essential for protein synthesis and implicated in hyperhomocysteinemia, has been the subject of numerous studies investigating its association with venous thromboembolism (VTE). However, the relationship between common single nucleotide polymorphisms (SNPs) in MTHFR and VTE remains complex and multifactorial, with larger meta-analyses refuting early suggestions of a significant association.

Key Points

• MTHFR is an essential enzyme that catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, necessary for protein synthesis.
• Common MTHFR SNPs, particularly C677T and A1298C, are associated with reduced enzyme activity and increased homocysteine levels.
• Homocysteine levels are influenced by various factors, including renal disease, thyroid disease, nutritional deficiencies, and alcohol intake.
• Larger meta-analyses have found no evidence for an association between homozygotes for the MTHFR C677T variant and VTE.
• Routine testing for MTHFR variants is not recommended due to the lack of evidence for a significant association with thrombotic risk.

The art of simplicity is a puzzle of complexity.
– Douglas Horton

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