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Primary topic: CTH gene DNA analysis

CTH Gene and Metabolism: What It Can Mean in a Pathway Report

CTH becomes more useful when sulfur / transsulfuration looks like a meaningful follow-up area instead of just background context.

What is the CTH gene?

CTH contributes to sulfur outflow after CBS. That makes it more useful as part of a pathway view than as an isolated SNP call.

How CTH affects metabolism

If CTH-related support is less favorable, the pathway can look more pressured under load and the linked biomarkers become more useful to validate directly.

What happens when CTH is altered

An altered CTH pattern does not diagnose anything on its own, but it does change which follow-up markers deserve attention first.

Curated SNP evidence for CTH

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.

Sulfur / transsulfuration

Evidence-backed report connection

CTH currently has 2 curated SNPs, 6 claim-level scores, and 1 claims eligible for pathway scoring.

Open the sample report
rs1021737CTH supporting signal3 claims · 6 study rows

enzyme activity · TT

CTH enzyme activity

Moderate

rs1021737 TT is associated with reduced CTH enzyme activity.

CTH rs1021737 is scored as a lower cystathionine gamma-lyase activity tendency for T-containing genotypes, strongest for TT and more conservative for GT.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportModerate support
Report useIncluded in pathway scoring
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1021737 in CTH, the cystathionine gamma-lyase gene. CTH encodes an enzyme involved in sulfur amino acid metabolism and hydrogen sulfide production.PubMed 34061822functional assay · directThe PubMed record for Sueiro-Olivares and colleagues reports that recombinant CTH carrying rs1021737 S403I had significantly reduced enzymatic activity compared with the reference enzyme, measured by relative hydrogen sulfide production. The figure caption also reports TT human macrophage data compared with GG and GT.

enzyme activity · GT

CTH enzyme activity

Not used for pathway scoring

rs1021737 GT is associated with reduced CTH enzyme activity.

CTH rs1021737 is scored as a lower cystathionine gamma-lyase activity tendency for T-containing genotypes, strongest for TT and more conservative for GT.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportModerate support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1021737 in CTH, the cystathionine gamma-lyase gene. CTH encodes an enzyme involved in sulfur amino acid metabolism and hydrogen sulfide production.PubMed 34061822functional assay · directThe PubMed record for Sueiro-Olivares and colleagues reports that recombinant CTH carrying rs1021737 S403I had significantly reduced enzymatic activity compared with the reference enzyme, measured by relative hydrogen sulfide production. The figure caption also reports TT human macrophage data compared with GG and GT.

enzyme activity · GG

CTH enzyme activity

Not used for pathway scoring

rs1021737 GG has no scored directional claim for CTH enzyme activity.

CTH rs1021737 is scored as a lower cystathionine gamma-lyase activity tendency for T-containing genotypes, strongest for TT and more conservative for GT.

Likely effectNo clear enzyme signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1021737 in CTH, the cystathionine gamma-lyase gene. CTH encodes an enzyme involved in sulfur amino acid metabolism and hydrogen sulfide production.PubMed 34061822functional assay · directThe PubMed record for Sueiro-Olivares and colleagues reports that recombinant CTH carrying rs1021737 S403I had significantly reduced enzymatic activity compared with the reference enzyme, measured by relative hydrogen sulfide production. The figure caption also reports TT human macrophage data compared with GG and GT.
rs482843CTH supporting signal3 claims · 6 study rows

unknown · AA

CTH unscored target

Not used for pathway scoring

rs482843 AA has no scored directional claim for CTH unscored target.

No reliable end-user genotype effect is assigned for CTH rs482843. Treat AA, AG, and GG as unscored in this simplified file.

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 lists rs482843 as a single-nucleotide variant with A and G alleles. This supports the genotype letters used here, but it does not by itself establish an enzyme or biomarker effect.PubMed 18701025other · loose proxyA human study selected rs482843 as a CTH gene polymorphism for essential-hypertension testing and reported no significant case-control association. The authors stated that replication and functional studies were still needed, so this record does not assign a directional genotype effect.

unknown · AG

CTH unscored target

Not used for pathway scoring

rs482843 AG has no scored directional claim for CTH unscored target.

No reliable end-user genotype effect is assigned for CTH rs482843. Treat AA, AG, and GG as unscored in this simplified file.

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 lists rs482843 as a single-nucleotide variant with A and G alleles. This supports the genotype letters used here, but it does not by itself establish an enzyme or biomarker effect.PubMed 18701025other · loose proxyA human study selected rs482843 as a CTH gene polymorphism for essential-hypertension testing and reported no significant case-control association. The authors stated that replication and functional studies were still needed, so this record does not assign a directional genotype effect.

unknown · GG

CTH unscored target

Not used for pathway scoring

rs482843 GG has no scored directional claim for CTH unscored target.

No reliable end-user genotype effect is assigned for CTH rs482843. Treat AA, AG, and GG as unscored in this simplified file.

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 lists rs482843 as a single-nucleotide variant with A and G alleles. This supports the genotype letters used here, but it does not by itself establish an enzyme or biomarker effect.PubMed 18701025other · loose proxyA human study selected rs482843 as a CTH gene polymorphism for essential-hypertension testing and reported no significant case-control association. The authors stated that replication and functional studies were still needed, so this record does not assign a directional genotype effect.

Common symptoms people report

  • sulfur / transsulfuration can overlap with more persistent symptom patterns
  • marker-driven follow-up may matter more than generic advice
  • mixed responses can make the pathway easier to miss without structured review

Biomarkers to validate

Homocysteine

Primary follow-up marker for CTH inside sulfur / transsulfuration.

Related pathway markers

Useful when the pathway needs to be validated as a system rather than as one variant.

Where DNA analysis helps

DNA helps decide whether CTH should move sulfur / transsulfuration higher on the follow-up list before broad interventions are assumed.

Example interpretation

CTH can strengthen the case for sulfur / transsulfuration follow-up when the rest of the pathway points in a similar direction.

Suggested validation: Homocysteine.

What to do next

  • Use Homocysteine and pathway context before assuming the gene matters in practice.
  • Read CTH alongside the related genes in the same pathway instead of as a standalone result.

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

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Related pages

CBS

CBS gene methylation

SUOX

SUOX gene DNA analysis

Choline status

choline status and methyl donor support

Cysteine, sulfate, and transsulfuration

Cysteine, sulfate, and transsulfuration DNA follow-up

B12 transport and recycling pathway

B12 transport and recycling pathway

Choline and phosphatidylcholine pathway

choline and phosphatidylcholine pathway

Can DNA predict metabolism?

can DNA predict metabolism

23andMe vs Metastate metabolism report

23andMe vs Metastate metabolism report

Related symptom angle

Brain fog metabolism causes

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