Description
Methylenetetrahydrofolate reductase (MTHFR) polymorphism testing is frequently ordered by physicians as part of the clinical investigation for thrombophilia. It was previously hypothesized that reduced enzyme activity of MTHFR led to mild hyperhomocysteinemia which led to an increaswed risck for venous thromboembolism, coronary heart disease, and recurrent pregnany loss. There are two commonly recognized polymorphic variants in the gene encoding for this enzyme; the “thermolabile” variant c.655C→T (p.Ala222Val), historically more commonly referred to as C677T, and the c.1286A→C (p.Glu429Ala) variant; both are known to decrease enzyme activity.
Indications
In general, the following genotypes currently appear unlikely to be of clinical significance:“thermolabile” variant c.655C→T heterozygote, c.1286A→C homozygote, or compound heterozygote. There are rare individuals with triple variant MTHFR genotypes (i.e., individuals who are homozygous for one variant and heterozygous for the other) may have resulting clinical risks, although that is currently speculative.
Sample Type, Quantity & Conditions
2 ml EDTA Whole Blood Room Temperature
Special Precautions
Collect in EDTA vacutainer tube. Avoid contamination with DNA of phlebotomist. Avoid haemolysed samples. Do not freeze samples. Send tube unopened.
Normal Range
Negative
