Test guide
MTHFR Gene Test
An MTHFR gene test checks a sample of your blood for two very common changes in a gene called MTHFR . Changes in your genes are also called gene variants or mutations.
What it is for
An MTHFR gene test looks for the two most common MTHFR gene variants. These are called C677T and A1298C. It can be done alone or as part of a group of genetic tests. Having either of these variants does not necessarily increase your risk for any health condition. Nor does it guarantee that you will have high homocysteine levels. So, your health care provider may only check for these variants if a homocysteine blood test has already shown that your homocysteine levels are high. Source: MedlinePlus, National Library of Medicine. Medical test information is public domain. Source identity and definition checked automatically on 2026-10-18. No individual clinical interpretation or human reviewer is asserted.
Limitations
Reference intervals and interpretation depend on the laboratory, specimen, method and clinical context. This source definition is educational information; it does not establish a diagnosis, product approval or suitability for an individual.
Also known as
- methylenetetrahydrofolate reductase mutation, C677T and A1298C, MTHFR DNA assay, MTHFR DNA testing, MTHFR gene variants, MTHFR gene polymorphisms 677T>
- C & 1298A>
- C mutations
Reviewed products
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