rs1801133
MTHFRrs1801133 is a single-nucleotide polymorphism (SNP) in the MTHFR gene. Genespiral reads it in the Health & Wellness analysis to describe Folate Metabolism (MTHFR C677T).
- Gene
- MTHFR
- Alleles
- A / G
- Genotypes
- GG, AG, AA
- Traits
- 1 trait across 1 analysis
An rsID such as rs1801133 is the reference number dbSNP assigns to one position in the genome where people commonly differ by a single letter. Raw data exports from 23andMe and AncestryDNA list your two alleles at that position as a genotype - for this marker one of GG, AG, AA. The order of the two letters carries no meaning, so AG and its reverse are the same genotype.
Alleles on this page are written on the forward (plus) strand, matching how consumer raw files report them. Other references sometimes describe the same variant on the opposite strand, which swaps A↔T and C↔G - see why the same variant can look different. The associations below are educational summaries of published research; they are not diagnoses, and the effect of any single SNP is usually modest.
Folate Metabolism (MTHFR C677T)
Metabolic and Nutritional · Part of the Health & Wellness analysis
The common MTHFR C677T variant produces a less stable enzyme, reducing conversion of folate into its active form and modestly raising homocysteine.
| Genotype | Association |
|---|---|
| GG | Typical MTHFR activity |
| AG | Moderately reduced activity |
| AA | Reduced activity (~30% of normal) |
- Summary
- MTHFR genotype affects folate processing; the reduced-activity form is very common and usually of minor consequence with adequate folate intake.
- Scientific insights
- The 'AA' genotype has the lowest enzyme activity, though effects are generally mild with sufficient dietary folate. (Reported on the forward strand, so 'A' is the classic 677T allele.)
- Lifestyle tips
- Adequate folate from diet (leafy greens, legumes) supports normal homocysteine metabolism regardless of genotype.
Check your genotype at rs1801133
Load your raw DNA file and Genespiral looks up rs1801133 along with every other marker in the Health & Wellness analysis. The file is parsed in your browser and never uploaded, so your genotype stays on your device.
- 1. Download your raw data from 23andMe or AncestryDNA.
- 2. Open the analysis below and choose the file.
- 3. Find Folate Metabolism (MTHFR C677T) in your results.
Related
References
Primary databases for this variant. Use them to check allele orientation, population frequencies, and the underlying studies.
- dbSNP entry for rs1801133 - NCBI
- rs1801133 variant page - Ensembl
- rs1801133 summary - SNPedia
- Clinical significance records for rs1801133 - ClinVar
- MTHFR gene - NCBI Gene
Genespiral is an educational tool, not a medical service. Genetic associations describe tendencies observed across populations, not certainties for you. Read the full disclaimer.