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Primary topic: BHMT gene function

BHMT Gene and Metabolism: What It Means for Your Body

BHMT is one of the key backup remethylation routes for homocysteine handling, making it important when methylation support and choline-derived methyl donors are under pressure.

What is the BHMT gene?

BHMT helps remethylate homocysteine using betaine-related methyl donors. It acts as a compensatory route when the folate-dependent side of methylation is under strain.

How BHMT affects metabolism

If BHMT support is less efficient, the system may have less backup capacity when methylation demand rises. That can matter most when MTHFR and PEMT-related pathways are already contributing pressure.

What happens when BHMT is altered

Altered BHMT signaling often matters as a support-capacity issue rather than a standalone defect. The practical question is whether the backup route is strong enough when the main route is strained.

Curated SNP evidence for BHMT

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.

Choline support Methylation

Evidence-backed report connection

BHMT currently has 3 curated SNPs, 9 claim-level scores, and 0 claims eligible for pathway scoring.

Open the sample report
rs3733890BHMT-742G>A3 claims · 12 study rows

enzyme activity · AA

BHMT enzyme activity

Not used for pathway scoring

rs3733890 AA has no scored directional claim for BHMT enzyme activity.

BHMT rs3733890 is currently not scored as changing total BHMT enzyme activity in this simplified model.

Likely effectNo clear enzyme signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP build 157 identifies rs3733890 as a G>A SNV at chr5:79126136 on GRCh38.p14, with BHMT consequence annotated as missense. The variant details show BHMT NM_001713.3:c.716G>A and NP_001704.2:p.Arg239Gln, supporting BHMT as the gene and A/G as the genotype-letter set used here.PubMed 18457970functional assay · directLi et al. functionally characterized common BHMT variation. The PubMed abstract states that BHMT wild-type and variant allozymes were expressed in COS-1 cells, and that variant allozymes showed no significant differences from wild type in enzyme activity or immunoreactive protein, although apparent Km values differed significantly. For this simplified enzyme-activity target, that supports direction 0 rather than a confident increase or decrease.Evidence 3functional assay · directFeng et al. measured BHMT enzyme activity and immunoreactive protein in 268 adult human liver biopsy samples and 73 fetal hepatic samples. The abstract emphasizes that BHMT protein levels correlated strongly with enzyme activity and that the work studied genotype-phenotype correlation, but the accessible institutional record does not provide a clear rs3733890 genotype-only direction suitable for a simplified per-genotype enzyme-activity score.Evidence 4other · directA later nutrition genetics article states that BHMT rs3733890 has been reported to produce an enzyme with higher affinity to homocysteine than wild genotype, citing Li et al. However, this is a kinetic-affinity statement, not a direct statement of higher total enzyme activity, and the same article reports no overall breast-cancer association for rs3733890. It is therefore used only as a caveat, not as a directional enzyme-activity assignment.

enzyme activity · AG

BHMT enzyme activity

Not used for pathway scoring

rs3733890 AG has no scored directional claim for BHMT enzyme activity.

BHMT rs3733890 is currently not scored as changing total BHMT enzyme activity in this simplified model.

Likely effectNo clear enzyme signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP build 157 identifies rs3733890 as a G>A SNV at chr5:79126136 on GRCh38.p14, with BHMT consequence annotated as missense. The variant details show BHMT NM_001713.3:c.716G>A and NP_001704.2:p.Arg239Gln, supporting BHMT as the gene and A/G as the genotype-letter set used here.PubMed 18457970functional assay · directLi et al. functionally characterized common BHMT variation. The PubMed abstract states that BHMT wild-type and variant allozymes were expressed in COS-1 cells, and that variant allozymes showed no significant differences from wild type in enzyme activity or immunoreactive protein, although apparent Km values differed significantly. For this simplified enzyme-activity target, that supports direction 0 rather than a confident increase or decrease.Evidence 3functional assay · directFeng et al. measured BHMT enzyme activity and immunoreactive protein in 268 adult human liver biopsy samples and 73 fetal hepatic samples. The abstract emphasizes that BHMT protein levels correlated strongly with enzyme activity and that the work studied genotype-phenotype correlation, but the accessible institutional record does not provide a clear rs3733890 genotype-only direction suitable for a simplified per-genotype enzyme-activity score.Evidence 4other · directA later nutrition genetics article states that BHMT rs3733890 has been reported to produce an enzyme with higher affinity to homocysteine than wild genotype, citing Li et al. However, this is a kinetic-affinity statement, not a direct statement of higher total enzyme activity, and the same article reports no overall breast-cancer association for rs3733890. It is therefore used only as a caveat, not as a directional enzyme-activity assignment.

enzyme activity · GG

BHMT enzyme activity

Not used for pathway scoring

rs3733890 GG has no scored directional claim for BHMT enzyme activity.

BHMT rs3733890 is currently not scored as changing total BHMT enzyme activity in this simplified model.

Likely effectNo clear enzyme signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP build 157 identifies rs3733890 as a G>A SNV at chr5:79126136 on GRCh38.p14, with BHMT consequence annotated as missense. The variant details show BHMT NM_001713.3:c.716G>A and NP_001704.2:p.Arg239Gln, supporting BHMT as the gene and A/G as the genotype-letter set used here.PubMed 18457970functional assay · directLi et al. functionally characterized common BHMT variation. The PubMed abstract states that BHMT wild-type and variant allozymes were expressed in COS-1 cells, and that variant allozymes showed no significant differences from wild type in enzyme activity or immunoreactive protein, although apparent Km values differed significantly. For this simplified enzyme-activity target, that supports direction 0 rather than a confident increase or decrease.Evidence 3functional assay · directFeng et al. measured BHMT enzyme activity and immunoreactive protein in 268 adult human liver biopsy samples and 73 fetal hepatic samples. The abstract emphasizes that BHMT protein levels correlated strongly with enzyme activity and that the work studied genotype-phenotype correlation, but the accessible institutional record does not provide a clear rs3733890 genotype-only direction suitable for a simplified per-genotype enzyme-activity score.Evidence 4other · directA later nutrition genetics article states that BHMT rs3733890 has been reported to produce an enzyme with higher affinity to homocysteine than wild genotype, citing Li et al. However, this is a kinetic-affinity statement, not a direct statement of higher total enzyme activity, and the same article reports no overall breast-cancer association for rs3733890. It is therefore used only as a caveat, not as a directional enzyme-activity assignment.
rs567754BHMT supporting signal3 claims · 9 study rows

biomarker tendency · TT

BHMT biomarker tendency

Not used for pathway scoring

rs567754 TT is associated with reduced BHMT biomarker tendency.

BHMT rs567754 is scored as a weak lipid-biomarker tendency, not as a direct BHMT enzyme-activity result.

Likely effectLower biomarker tendency
Signal sizeSmall signal
Evidence supportLimited support
Report useEvidence only, not scored
Show study evidence
PMC3053054functional assay · loose proxyThe human liver BHMT genotype-phenotype study found no significant single-SNP correlation for rs567754 with BHMT enzyme activity or protein level. This null functional result is not scored in the triglyceride biomarker direction.Evidence 2gwas · close proxyGWAS Catalog association 215563403 reports rs567754-T for triglycerides in small VLDL, p 4e-11, with beta direction decrease and beta unit mmol/L.Evidence 3gwas · close proxyGWAS Catalog association 215565652 reports rs567754-T for triglyceride-to-phosphoglyceride ratio, p 1e-10, with beta direction decrease and beta unit ratio.

biomarker tendency · CT

BHMT biomarker tendency

Not used for pathway scoring

rs567754 CT is associated with reduced BHMT biomarker tendency.

BHMT rs567754 is scored as a weak lipid-biomarker tendency, not as a direct BHMT enzyme-activity result.

Likely effectLower biomarker tendency
Signal sizeSmall signal
Evidence supportLimited support
Report useEvidence only, not scored
Show study evidence
PMC3053054functional assay · loose proxyThe human liver BHMT genotype-phenotype study found no significant single-SNP correlation for rs567754 with BHMT enzyme activity or protein level. This null functional result is not scored in the triglyceride biomarker direction.Evidence 2gwas · close proxyGWAS Catalog association 215563403 reports rs567754-T for triglycerides in small VLDL, p 4e-11, with beta direction decrease and beta unit mmol/L.Evidence 3gwas · close proxyGWAS Catalog association 215565652 reports rs567754-T for triglyceride-to-phosphoglyceride ratio, p 1e-10, with beta direction decrease and beta unit ratio.

biomarker tendency · CC

BHMT biomarker tendency

Not used for pathway scoring

rs567754 CC has no scored directional claim for BHMT biomarker tendency.

BHMT rs567754 is scored as a weak lipid-biomarker tendency, not as a direct BHMT enzyme-activity result.

Likely effectNo clear biomarker tendency
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
PMC3053054functional assay · loose proxyThe human liver BHMT genotype-phenotype study found no significant single-SNP correlation for rs567754 with BHMT enzyme activity or protein level. This null functional result is not scored in the triglyceride biomarker direction.Evidence 2gwas · close proxyGWAS Catalog association 215563403 reports rs567754-T for triglycerides in small VLDL, p 4e-11, with beta direction decrease and beta unit mmol/L.Evidence 3gwas · close proxyGWAS Catalog association 215565652 reports rs567754-T for triglyceride-to-phosphoglyceride ratio, p 1e-10, with beta direction decrease and beta unit ratio.
rs651852BHMT supporting signal3 claims · 6 study rows

unknown · CC

BHMT unscored target

Not used for pathway scoring

rs651852 CC has no scored directional claim for BHMT unscored target.

BHMT rs651852 is currently not scored for a metabolic effect because the curated evidence is exploratory and not strong enough for a clear user-facing genotype effect.

Likely effectNo clear DNA signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
PubMed 10biomarker association · loose proxyA small exploratory fortified-beverage study reported a significant main genetic effect of rs651852 on serum isoleucine, leucine, and valine at 120 minutes. The paper states that homozygous A in its reported notation had lower branched-chain amino acid concentrations than G-allele counterparts, and that the finding needs validation in a larger cohort. This is treated as insufficient for a user-facing genotype score.Evidence 2other · loose proxyEnsembl VEP/variation data checked through the REST endpoint mapped rs651852 as an intron variant overlapping BHMT, with modifier predicted impact rather than a coding enzyme-change annotation.

unknown · CT

BHMT unscored target

Not used for pathway scoring

rs651852 CT has no scored directional claim for BHMT unscored target.

BHMT rs651852 is currently not scored for a metabolic effect because the curated evidence is exploratory and not strong enough for a clear user-facing genotype effect.

Likely effectNo clear DNA signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
PubMed 10biomarker association · loose proxyA small exploratory fortified-beverage study reported a significant main genetic effect of rs651852 on serum isoleucine, leucine, and valine at 120 minutes. The paper states that homozygous A in its reported notation had lower branched-chain amino acid concentrations than G-allele counterparts, and that the finding needs validation in a larger cohort. This is treated as insufficient for a user-facing genotype score.Evidence 2other · loose proxyEnsembl VEP/variation data checked through the REST endpoint mapped rs651852 as an intron variant overlapping BHMT, with modifier predicted impact rather than a coding enzyme-change annotation.

unknown · TT

BHMT unscored target

Not used for pathway scoring

rs651852 TT has no scored directional claim for BHMT unscored target.

BHMT rs651852 is currently not scored for a metabolic effect because the curated evidence is exploratory and not strong enough for a clear user-facing genotype effect.

Likely effectNo clear DNA signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
PubMed 10biomarker association · loose proxyA small exploratory fortified-beverage study reported a significant main genetic effect of rs651852 on serum isoleucine, leucine, and valine at 120 minutes. The paper states that homozygous A in its reported notation had lower branched-chain amino acid concentrations than G-allele counterparts, and that the finding needs validation in a larger cohort. This is treated as insufficient for a user-facing genotype score.Evidence 2other · loose proxyEnsembl VEP/variation data checked through the REST endpoint mapped rs651852 as an intron variant overlapping BHMT, with modifier predicted impact rather than a coding enzyme-change annotation.

Common symptoms people report

  • fatigue or brain fog with methylation-related patterns
  • poor tolerance to heavy methylation supplement experimentation
  • concern about homocysteine despite otherwise normal labs
  • sensitivity to low-choline or low-betaine intake

Biomarkers to validate

Homocysteine

Helps assess whether backup remethylation appears insufficient.

Choline-related diet context

Important for understanding whether substrate availability is part of the issue.

Vitamin B12 and folate

Provides context for the broader methylation picture.

Where DNA analysis helps

DNA can show whether remethylation backup capacity deserves attention before random supplement changes. It helps prioritize what to validate and what to compare across pathways.

Example Insight

Your backup remethylation pathway may contribute less buffering than expected when methylation demand is high.

Suggested validation: homocysteine with folate and B12 context.

What to do next

  • Check homocysteine before assuming a methylation block.
  • Review BHMT with MTHFR and PEMT when methylation and choline overlap.
  • Use diet and biomarker context to decide whether the signal is active.

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

Get My DNA Report

Related pages

MTHFR

MTHFR gene metabolism

PEMT

PEMT gene choline metabolism

Choline status

choline status and methyl donor support

Holotranscobalamin

holotranscobalamin and B12 transport

B12 transport and recycling pathway

B12 transport and recycling pathway

Choline and phosphatidylcholine pathway

choline and phosphatidylcholine pathway

Is DNA metabolism analysis worth it?

is DNA metabolism analysis worth it

DNA nutrition analysis report

DNA nutrition analysis report

Related symptom angle

Slow metabolism genetics

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