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Primary topic: SLC19A1 folate transport gene

SLC19A1 Gene and Metabolism: What It Means for Your Body

SLC19A1 becomes relevant when folate availability looks less reliable than intake alone would suggest.

What is the SLC19A1 gene?

SLC19A1 helps move reduced folates into cells. That means it affects whether folate can actually support one-carbon metabolism where it is needed.

How SLC19A1 affects metabolism

If folate transport is less efficient, methylation support can feel strained even when intake looks acceptable. That shifts attention toward homocysteine, folate status, and broader one-carbon context.

What happens when SLC19A1 is altered

Altered transport does not automatically mean poor folate status, but it increases the value of validating folate-related support rather than assuming intake solves the issue.

Curated SNP evidence for SLC19A1

These SNPs come from the approved study-level evidence model. Each claim is scored from curated study rows, then gated before it can influence pathway scoring.

Methylation

Evidence-backed report connection

SLC19A1 currently has 2 curated SNPs, 6 claim-level scores, and 0 claims eligible for pathway scoring.

Open the sample report
rs105126680G>A3 claims · 9 study rows

transport activity · CC

SLC19A1 transport activity

Not used for pathway scoring

rs1051266 CC has no scored directional claim for SLC19A1 transport activity.

SLC19A1 rs1051266 is not scored as a clear reduced-folate-carrier activity change from the common C/T genotype alone.

Likely effectNo clear transport signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1051266 in SLC19A1, the reduced folate carrier gene, and annotate it as a coding missense variant. The common genomic genotype letters represented here are C and T.ClinVar recordclinical curation · close proxyClinVar Variation ID 157588 includes rs1051266 submissions in drug-response and benign contexts. This supports treating the variant cautiously and not using it as a disease-risk or folate-deficiency diagnosis.PubMed 11705857functional assay · directWhetstine et al. characterized the common SLC19A1 position-80 variant and tested the two protein forms in transport-impaired cells. Their abstract reports nearly identical uptake rates for methotrexate and 5-formyl tetrahydrofolate, with no significant difference in methotrexate transport kinetic parameters. This supports a neutral common-genotype transport score.

transport activity · CT

SLC19A1 transport activity

Not used for pathway scoring

rs1051266 CT has no scored directional claim for SLC19A1 transport activity.

SLC19A1 rs1051266 is not scored as a clear reduced-folate-carrier activity change from the common C/T genotype alone.

Likely effectNo clear transport signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1051266 in SLC19A1, the reduced folate carrier gene, and annotate it as a coding missense variant. The common genomic genotype letters represented here are C and T.ClinVar recordclinical curation · close proxyClinVar Variation ID 157588 includes rs1051266 submissions in drug-response and benign contexts. This supports treating the variant cautiously and not using it as a disease-risk or folate-deficiency diagnosis.PubMed 11705857functional assay · directWhetstine et al. characterized the common SLC19A1 position-80 variant and tested the two protein forms in transport-impaired cells. Their abstract reports nearly identical uptake rates for methotrexate and 5-formyl tetrahydrofolate, with no significant difference in methotrexate transport kinetic parameters. This supports a neutral common-genotype transport score.

transport activity · TT

SLC19A1 transport activity

Not used for pathway scoring

rs1051266 TT has no scored directional claim for SLC19A1 transport activity.

SLC19A1 rs1051266 is not scored as a clear reduced-folate-carrier activity change from the common C/T genotype alone.

Likely effectNo clear transport signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1051266 in SLC19A1, the reduced folate carrier gene, and annotate it as a coding missense variant. The common genomic genotype letters represented here are C and T.ClinVar recordclinical curation · close proxyClinVar Variation ID 157588 includes rs1051266 submissions in drug-response and benign contexts. This supports treating the variant cautiously and not using it as a disease-risk or folate-deficiency diagnosis.PubMed 11705857functional assay · directWhetstine et al. characterized the common SLC19A1 position-80 variant and tested the two protein forms in transport-impaired cells. Their abstract reports nearly identical uptake rates for methotrexate and 5-formyl tetrahydrofolate, with no significant difference in methotrexate transport kinetic parameters. This supports a neutral common-genotype transport score.
rs2838958SLC19A1 supporting signal3 claims · 9 study rows

unknown · AA

SLC19A1 unscored target

Not used for pathway scoring

rs2838958 AA has no scored directional claim for SLC19A1 unscored target.

SLC19A1 rs2838958 is currently not scored for a clear end-user metabolic effect.

Likely effectNo clear DNA signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs2838958 in SLC19A1 and annotate it as an intron variant. The common genotype letters represented here are A and G.PubMed 28525903other · loose proxyLiu et al. studied methotrexate transporter polymorphisms in children with acute lymphoblastic leukemia. Their abstract reports an association between SLC19A1 rs2838958 AA and poorer event-free survival compared with AG or GG, but this is a treatment-outcome association rather than a direct measurement of folate transport, gene expression, or a routine metabolic biomarker.PMC11505744other · loose proxyA later pediatric acute lymphoblastic leukemia study genotyped rs2838958 along with other SLC19A1 markers during methotrexate treatment. The article reports no statistically significant individual association between rs2838958 and mucositis, hepatotoxicity, or other adverse-event groups in that sample. This lowers confidence in assigning any general metabolic direction.

unknown · AG

SLC19A1 unscored target

Not used for pathway scoring

rs2838958 AG has no scored directional claim for SLC19A1 unscored target.

SLC19A1 rs2838958 is currently not scored for a clear end-user metabolic effect.

Likely effectNo clear DNA signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs2838958 in SLC19A1 and annotate it as an intron variant. The common genotype letters represented here are A and G.PubMed 28525903other · loose proxyLiu et al. studied methotrexate transporter polymorphisms in children with acute lymphoblastic leukemia. Their abstract reports an association between SLC19A1 rs2838958 AA and poorer event-free survival compared with AG or GG, but this is a treatment-outcome association rather than a direct measurement of folate transport, gene expression, or a routine metabolic biomarker.PMC11505744other · loose proxyA later pediatric acute lymphoblastic leukemia study genotyped rs2838958 along with other SLC19A1 markers during methotrexate treatment. The article reports no statistically significant individual association between rs2838958 and mucositis, hepatotoxicity, or other adverse-event groups in that sample. This lowers confidence in assigning any general metabolic direction.

unknown · GG

SLC19A1 unscored target

Not used for pathway scoring

rs2838958 GG has no scored directional claim for SLC19A1 unscored target.

SLC19A1 rs2838958 is currently not scored for a clear end-user metabolic effect.

Likely effectNo clear DNA signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs2838958 in SLC19A1 and annotate it as an intron variant. The common genotype letters represented here are A and G.PubMed 28525903other · loose proxyLiu et al. studied methotrexate transporter polymorphisms in children with acute lymphoblastic leukemia. Their abstract reports an association between SLC19A1 rs2838958 AA and poorer event-free survival compared with AG or GG, but this is a treatment-outcome association rather than a direct measurement of folate transport, gene expression, or a routine metabolic biomarker.PMC11505744other · loose proxyA later pediatric acute lymphoblastic leukemia study genotyped rs2838958 along with other SLC19A1 markers during methotrexate treatment. The article reports no statistically significant individual association between rs2838958 and mucositis, hepatotoxicity, or other adverse-event groups in that sample. This lowers confidence in assigning any general metabolic direction.

Common symptoms people report

  • poor response to folate-focused support
  • brain fog or low mental sharpness
  • fatigue when methylation demand is high

Biomarkers to validate

Homocysteine

Useful for checking whether one-carbon flow is pressured.

Folate markers

Adds direct substrate context.

Vitamin B12

Helps separate folate transport from broader methylation strain.

Where DNA analysis helps

DNA helps flag when folate transport deserves more attention than generic folate advice would suggest.

Example Insight

Your folate-delivery step may be part of the methylation picture even when folate intake alone looks reasonable.

Suggested validation: homocysteine plus folate status.

What to do next

  • Compare folate markers with homocysteine before acting on transport assumptions.
  • Review SLC19A1 together with MTHFR and SHMT1 in methylation-focused cases.
  • Use biomarker context before escalating folate strategies.

Upload your DNA file and receive a structured metabolic pathway analysis with prioritized insights and suggested validation markers.

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Related pages

MTHFR

MTHFR gene metabolism

SHMT1

SHMT1 gene metabolism

Holotranscobalamin

holotranscobalamin and B12 transport

Homocysteine

homocysteine and methylation

B12 transport and recycling pathway

B12 transport and recycling pathway

Methylation pathway

methylation pathway explained

Is DNA metabolism analysis worth it?

is DNA metabolism analysis worth it

DNA nutrition analysis report

DNA nutrition analysis report

Related symptom angle

Why supplements do not work for me

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