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Primary topic: AOC1 histamine clearance gene

AOC1 Gene and Metabolism: What It Means for Your Body

AOC1 becomes relevant when histamine-clearance capacity looks weaker than symptom tracking alone can explain.

What is the AOC1 gene?

AOC1 encodes diamine oxidase activity in a broader extracellular histamine-clearance context. It overlaps with the practical histamine-clearance questions many people already associate with DAO.

How AOC1 affects metabolism

If AOC1-related support is lower, dietary and gut-derived histamine can become harder to clear efficiently. That matters most when symptoms cluster around meals or load.

What happens when AOC1 is altered

Altered AOC1 function does not prove histamine intolerance, but it raises the value of using a real clearance-focused follow-up instead of guessing.

Curated SNP evidence for AOC1

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.

Histamine Inflammation / immune signaling

Evidence-backed report connection

AOC1 currently has 4 curated SNPs, 12 claim-level scores, and 2 claims eligible for pathway scoring.

Open the sample report
rs10156191AOC1 supporting signal, DAO supporting signal3 claims · 9 study rows

enzyme activity · TT

AOC1 enzyme activity

Not used for pathway scoring

rs10156191 TT is associated with reduced AOC1 enzyme activity.

AOC1 rs10156191 is scored as a lower diamine oxidase activity tendency for T-containing genotypes, with a stronger tendency for TT than CT.

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 rs10156191 in AOC1 and annotate it on AOC1 transcripts as c.47C>T, a Thr-to-Met amino acid substitution in diamine oxidase.PubMed 21488903biomarker association · loose proxyMaintz et al. studied DAO variants and serum DAO activity in German participants. The PubMed abstract reports that the minor allele at rs10156191 was associated with higher risk of reduced DAO activity, and that DAO variants influence DAO expression and activity but are not sufficient by themselves to define histamine intolerance.PubMed 10biomarker association · loose proxyAgundez et al. describe rs10156191 as the DAO Thr16Met polymorphism. The article states that the 16Met variant results in reduced serum DAO activity and that T-containing genotypes were more frequent in the studied NSAID hypersensitivity group.

enzyme activity · CT

AOC1 enzyme activity

Not used for pathway scoring

rs10156191 CT is associated with reduced AOC1 enzyme activity.

AOC1 rs10156191 is scored as a lower diamine oxidase activity tendency for T-containing genotypes, with a stronger tendency for TT than CT.

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 rs10156191 in AOC1 and annotate it on AOC1 transcripts as c.47C>T, a Thr-to-Met amino acid substitution in diamine oxidase.PubMed 21488903biomarker association · loose proxyMaintz et al. studied DAO variants and serum DAO activity in German participants. The PubMed abstract reports that the minor allele at rs10156191 was associated with higher risk of reduced DAO activity, and that DAO variants influence DAO expression and activity but are not sufficient by themselves to define histamine intolerance.PubMed 10biomarker association · loose proxyAgundez et al. describe rs10156191 as the DAO Thr16Met polymorphism. The article states that the 16Met variant results in reduced serum DAO activity and that T-containing genotypes were more frequent in the studied NSAID hypersensitivity group.

enzyme activity · CC

AOC1 enzyme activity

Not used for pathway scoring

rs10156191 CC has no scored directional claim for AOC1 enzyme activity.

AOC1 rs10156191 is scored as a lower diamine oxidase activity tendency for T-containing genotypes, with a stronger tendency for TT than CT.

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 rs10156191 in AOC1 and annotate it on AOC1 transcripts as c.47C>T, a Thr-to-Met amino acid substitution in diamine oxidase.PubMed 21488903biomarker association · loose proxyMaintz et al. studied DAO variants and serum DAO activity in German participants. The PubMed abstract reports that the minor allele at rs10156191 was associated with higher risk of reduced DAO activity, and that DAO variants influence DAO expression and activity but are not sufficient by themselves to define histamine intolerance.PubMed 10biomarker association · loose proxyAgundez et al. describe rs10156191 as the DAO Thr16Met polymorphism. The article states that the 16Met variant results in reduced serum DAO activity and that T-containing genotypes were more frequent in the studied NSAID hypersensitivity group.
rs1049742DAO supporting signal3 claims · 9 study rows

enzyme activity · TT

AOC1 enzyme activity

Not used for pathway scoring

rs1049742 TT is associated with reduced AOC1 enzyme activity.

AOC1 rs1049742 is scored as a possible mild lower diamine oxidase activity tendency for T-containing genotypes.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportLimited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1049742 in AOC1 and annotate it on AOC1 transcripts as c.995C>T, a Ser-to-Phe amino acid substitution in diamine oxidase.PubMed 21488903biomarker association · loose proxyMaintz et al. report in the PubMed abstract that the minor allele at rs1049742 was associated with higher risk of reduced DAO activity in both genotypic and allelic models.PubMed 17700358biomarker association · loose proxyAyuso et al. identified Ser332Phe among common nonsynonymous AOC1 variants, but their abstract describes the effect of the rare 332Phe allele as negligible compared with the stronger His645Asp signal. This supports conservative scoring for rs1049742.

enzyme activity · CT

AOC1 enzyme activity

Not used for pathway scoring

rs1049742 CT is associated with reduced AOC1 enzyme activity.

AOC1 rs1049742 is scored as a possible mild lower diamine oxidase activity tendency for T-containing genotypes.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportLimited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1049742 in AOC1 and annotate it on AOC1 transcripts as c.995C>T, a Ser-to-Phe amino acid substitution in diamine oxidase.PubMed 21488903biomarker association · loose proxyMaintz et al. report in the PubMed abstract that the minor allele at rs1049742 was associated with higher risk of reduced DAO activity in both genotypic and allelic models.PubMed 17700358biomarker association · loose proxyAyuso et al. identified Ser332Phe among common nonsynonymous AOC1 variants, but their abstract describes the effect of the rare 332Phe allele as negligible compared with the stronger His645Asp signal. This supports conservative scoring for rs1049742.

enzyme activity · CC

AOC1 enzyme activity

Not used for pathway scoring

rs1049742 CC has no scored directional claim for AOC1 enzyme activity.

AOC1 rs1049742 is scored as a possible mild lower diamine oxidase activity tendency for T-containing genotypes.

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 rs1049742 in AOC1 and annotate it on AOC1 transcripts as c.995C>T, a Ser-to-Phe amino acid substitution in diamine oxidase.PubMed 21488903biomarker association · loose proxyMaintz et al. report in the PubMed abstract that the minor allele at rs1049742 was associated with higher risk of reduced DAO activity in both genotypic and allelic models.PubMed 17700358biomarker association · loose proxyAyuso et al. identified Ser332Phe among common nonsynonymous AOC1 variants, but their abstract describes the effect of the rare 332Phe allele as negligible compared with the stronger His645Asp signal. This supports conservative scoring for rs1049742.
rs1049793AOC1 supporting signal, DAO supporting signal3 claims · 9 study rows

enzyme activity · GG

AOC1 enzyme activity

Strong

rs1049793 GG is associated with reduced AOC1 enzyme activity.

AOC1 rs1049793 is scored as a lower diamine oxidase activity tendency for G-containing genotypes, with a stronger tendency for GG than CG.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportStrong support
Report useIncluded in pathway scoring
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1049793 in AOC1 and annotate the C>G allele on AOC1 transcripts as a His-to-Asp amino acid substitution in diamine oxidase.PubMed 17700358biomarker association · loose proxyAyuso et al. studied serum DAO activity by AOC1 genotype. The PubMed abstract reports that individuals carrying the 645Asp amino acid had lower serum DAO activity than noncarriers, with a gene-dose effect; heterozygotes had Vmax/Km values of 66% and homozygotes 51% compared with noncarriers.PubMed 10biomarker association · directAgundez et al. summarize prior DAO functional work and state that alleles encoding the 645Asp-containing protein can impair enzyme activity. The article also treats this as a functional DAO variant rather than a stand-alone diagnosis.

enzyme activity · CG

AOC1 enzyme activity

Strong

rs1049793 CG is associated with reduced AOC1 enzyme activity.

AOC1 rs1049793 is scored as a lower diamine oxidase activity tendency for G-containing genotypes, with a stronger tendency for GG than CG.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportStrong support
Report useIncluded in pathway scoring
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs1049793 in AOC1 and annotate the C>G allele on AOC1 transcripts as a His-to-Asp amino acid substitution in diamine oxidase.PubMed 17700358biomarker association · loose proxyAyuso et al. studied serum DAO activity by AOC1 genotype. The PubMed abstract reports that individuals carrying the 645Asp amino acid had lower serum DAO activity than noncarriers, with a gene-dose effect; heterozygotes had Vmax/Km values of 66% and homozygotes 51% compared with noncarriers.PubMed 10biomarker association · directAgundez et al. summarize prior DAO functional work and state that alleles encoding the 645Asp-containing protein can impair enzyme activity. The article also treats this as a functional DAO variant rather than a stand-alone diagnosis.

enzyme activity · CC

AOC1 enzyme activity

Not used for pathway scoring

rs1049793 CC has no scored directional claim for AOC1 enzyme activity.

AOC1 rs1049793 is scored as a lower diamine oxidase activity tendency for G-containing genotypes, with a stronger tendency for GG than CG.

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 rs1049793 in AOC1 and annotate the C>G allele on AOC1 transcripts as a His-to-Asp amino acid substitution in diamine oxidase.PubMed 17700358biomarker association · loose proxyAyuso et al. studied serum DAO activity by AOC1 genotype. The PubMed abstract reports that individuals carrying the 645Asp amino acid had lower serum DAO activity than noncarriers, with a gene-dose effect; heterozygotes had Vmax/Km values of 66% and homozygotes 51% compared with noncarriers.PubMed 10biomarker association · directAgundez et al. summarize prior DAO functional work and state that alleles encoding the 645Asp-containing protein can impair enzyme activity. The article also treats this as a functional DAO variant rather than a stand-alone diagnosis.
rs2052129DAO regulatory signal, DAO supporting signal3 claims · 9 study rows

expression · GT

AOC1 gene expression

Not used for pathway scoring

rs2052129 GT is associated with reduced AOC1 gene expression.

AOC1 rs2052129 is scored as a lower AOC1 expression tendency for T-containing genotypes, with a stronger tendency for TT than GT.

Likely effectLower gene expression signal
Signal sizeSmall signal
Evidence supportModerate support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs2052129 upstream of AOC1 transcripts, consistent with a regulatory rather than protein-coding variant.PubMed 21488903expression eqtl · directMaintz et al. report in the PubMed abstract that the minor allele at rs2052129 was associated with higher risk of reduced DAO activity, reporter assays showed lower promoter activity for the minor allele, and homozygous minor-allele carriers had lower DAO mRNA expression.PubMed 10expression eqtl · directAgundez et al. describe rs2052129 as a promoter variant that seems to decrease DAO transcriptional activity. In their NSAID hypersensitivity cohort, rs2052129 itself was not associated with hypersensitivity risk, supporting expression-only interpretation here.

expression · TT

AOC1 gene expression

Not used for pathway scoring

rs2052129 TT is associated with reduced AOC1 gene expression.

AOC1 rs2052129 is scored as a lower AOC1 expression tendency for T-containing genotypes, with a stronger tendency for TT than GT.

Likely effectLower gene expression signal
Signal sizeSmall signal
Evidence supportModerate support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs2052129 upstream of AOC1 transcripts, consistent with a regulatory rather than protein-coding variant.PubMed 21488903expression eqtl · directMaintz et al. report in the PubMed abstract that the minor allele at rs2052129 was associated with higher risk of reduced DAO activity, reporter assays showed lower promoter activity for the minor allele, and homozygous minor-allele carriers had lower DAO mRNA expression.PubMed 10expression eqtl · directAgundez et al. describe rs2052129 as a promoter variant that seems to decrease DAO transcriptional activity. In their NSAID hypersensitivity cohort, rs2052129 itself was not associated with hypersensitivity risk, supporting expression-only interpretation here.

expression · GG

AOC1 gene expression

Not used for pathway scoring

rs2052129 GG has no scored directional claim for AOC1 gene expression.

AOC1 rs2052129 is scored as a lower AOC1 expression tendency for T-containing genotypes, with a stronger tendency for TT than GT.

Likely effectNo clear expression signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
NCBI RefSNP recordidentity only · unknownNCBI RefSNP data place rs2052129 upstream of AOC1 transcripts, consistent with a regulatory rather than protein-coding variant.PubMed 21488903expression eqtl · directMaintz et al. report in the PubMed abstract that the minor allele at rs2052129 was associated with higher risk of reduced DAO activity, reporter assays showed lower promoter activity for the minor allele, and homozygous minor-allele carriers had lower DAO mRNA expression.PubMed 10expression eqtl · directAgundez et al. describe rs2052129 as a promoter variant that seems to decrease DAO transcriptional activity. In their NSAID hypersensitivity cohort, rs2052129 itself was not associated with hypersensitivity risk, supporting expression-only interpretation here.

Common symptoms people report

  • histamine-like reactions around meals
  • flushing or headaches with unclear triggers
  • more sensitivity under higher histamine load

Biomarkers to validate

DAO activity

Direct clearance-context marker.

Plasma histamine

Useful when reactions feel histamine-linked.

Trigger tracking

Practical context for load-driven symptoms.

Where DNA analysis helps

DNA can show whether extracellular histamine clearance deserves more attention in a pathway-based review.

Example Insight

Your histamine-clearance pathway may deserve follow-up because load handling can become the real constraint.

Suggested validation: DAO activity plus trigger tracking.

What to do next

  • Use DAO activity and trigger tracking before assuming genetics explains everything.
  • Review AOC1 with DAO and HNMT for a fuller clearance picture.
  • Treat the pathway as something to validate, not assume.

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

Get My DNA Report

Related pages

DAO

DAO gene histamine metabolism

HNMT

HNMT gene histamine metabolism

DAO activity

DAO activity and histamine clearance

Tryptase

tryptase and histamine context

Histamine clearance pathway

histamine clearance pathway

Inflammation and immune signaling pathway

inflammation immune signaling pathway

Is this medical advice?

is this medical advice

Generic DNA report vs pathway analysis

generic DNA report vs pathway analysis

Related symptom angle

Histamine intolerance genetics

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