What does the Methylenetetrahydrofolate Reductase A1298C Polymorphism test measure?

Why is Methylenetetrahydrofolate Reductase A1298C Polymorphism measured?

A1298C homozygosity and compound heterozygosity with C677T are associated with mildly reduced MTHFR activity but less consistently with hyperhomocysteinaemia than C677T alone. The variant is included in comprehensive MTHFR panels to complete the genotype picture, but its independent clinical significance for cardiovascular risk is weaker and more contested. As with C677T, interpretation should be anchored to measured homocysteine and folate status rather than genotype in isolation, and practitioners should counsel patients that genotype is not destiny and does not replace standard risk assessment.

Reference ranges

Standard reference

AA (wild-type), AC (heterozygous), CC (homozygous variant).

Functional medicine optimal

Not applicable (categorical genotype). Interpret with homocysteine and folate levels and the C677T genotype.

Units

genotype

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.