Abbrevation: MTHFR 667 PCR-RFLP
Test Name: Methylenetetrahydrofolat reductase2
Normal Range: -
To evaluate the cause of elevated homocysteine levels; sometimes to help determine your risk of thrombosis or premature cardiovascular disease (CVD)
When you have elevated homocysteine levels; sometimes when a close relative has MTHFR gene mutations or has developed CVD or thrombosis at an early age
A blood sample taken from a vein in your arm
The methylenetetrahydrofolate reductase (MTHFR) gene oversees the production of the MTHFR enzyme. This enzyme changes one form of folate into another and is part of the process that converts homocysteine into methionine, an important building block for many proteins.
MTHFR testing detects two relatively common DNA sequence variants (single nucleotide polymorphisms, SNPs) in the MTHFR gene, C677T and A1298C. These SNPs result in changes in the DNA (or mutations) and are associated with increased homocysteine levels in the blood, which may increase the risk of premature cardiovascular disease (CVD), thrombosis, and stroke. Approximately 10%of the British population is homozygous for C677T. The prevalence is higher in those of Mediterranean and lower in those of African or Indian Asian descent.
The C677T variant results in a less active form of the MTHFR enzyme. When a person has two copies of the MTHFR C677T gene mutation (homozygous) or one copy of MTHFR C677T and one copy of A1298C (compound heterozygous), decreased MTHFR enzyme activity slows down the homocysteine-to-methionine conversion process and can lead to a build-up of homocysteine in the blood.
The increase in homocysteine is often mild to moderate but will vary from person to person depending upon the amount MTHFR enzyme activity. The rise in homocysteine within the bloodstream is worsened when the affected person is folate-deficient.
Results of some studies suggest that high levels of homocysteine in the blood may contribute to risk of CVD by damaging blood vessel walls and promoting formation of plaque (atherosclerosis) and inappropriate blood clots (thrombosis). However, a direct link between homocysteine levels and CVD or thrombotic risk has not been proven. For more on this, see the article on Homocysteine.
How is the sample collected for testing?
A blood sample is obtained by inserting a needle into a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.