MTHFR VARIANT ANALYSIS

DNA ANALYSIS

Genetic risk factors are involved in the predisposition of individuals to venous thrombosis. These include increased plasma homocysteine levels, which is associated with homozygosity for a nucleotide variant in the methylenetetrahydrofolate reductase (MTHFR) gene. The MTHFR 677 C-T variant (leading to an alanine to valine substitution) results in a thermolabile enzyme and decreased production of folate, which is a cofactor required for homocysteine remethylation. Homozygosity for the MTHFR 677 C-T variant is associated with mild to moderate hyperhomocysteinemia. However, the exact thrombophilic risk conferred by the MTHFR 677 C-T thermolabile variant remains to be defined.

Analysis for the MTHFR 677 C-T variant is offered as a specific DNA test, or as part of a Thrombophilia panel which also includes the Factor V Leiden R506Q mutation and the Prothrombin (Factor II) 20210G-A mutation.

Reasons For Referral:

Evaluation of patients with venous thrombosis, particularly those with hyperhomocysteinemia.
Evaluation of asymptomatic individuals with a family history of venous thrombosis.
Evaluation of individuals with relatives known to have the MTHFR 677 C-T variant allele.

Testing Methodology:

Direct Mutation Analysis: Our laboratory uses an automated high-throughput system that incorporates DNA amplification (PCR), primer extension, and allele resolution by Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) Mass Spectrometry to test for the 677 C-T variant in the MTHFR gene.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adults: 14 cc; Child: 6 cc; Infant: 2-3 cc
Requistion form must accompany specimen. Prior to any genetic testing, we recommend genetic counseling and request that the subject sign our consent form and submit it with the sample. To receive our forms, additional information, or collection kits, please contact our laboratory.

Turnaround Time:

2 weeks

CPT Codes and Prices:

83914, 83912, 83898, 83891

Shipping Information

Forms:

>> Molecular Diagnostic Requisition

Test Codes:

6045