NutritionEvidence 1B

rs1801131 · MTHFR

Risk allele: C

Risk-Allele Phenotype

A1298C polymorphism moderately reduces MTHFR enzyme activity (~10-20%), potentially affecting folate status and homocysteine levels.

Reference-Allele Phenotype

Wild-type A allele supports normal MTHFR function and folate processing.

Evidence Level

1B — Strong — single high-quality study See methodology for how we grade evidence.

Cross-References

dbSNP — rs1801131
ClinVar — search rs1801131
NCBI Gene — MTHFR

Informational only

This page summarizes population-level evidence about a genetic variant. It is not a diagnosis. Your individual risk depends on your full genome, lifestyle, environment, and family history. Consult a healthcare provider for personalized medical advice.

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