AOC1 is the official gene symbol for amine oxidase copper containing 1. NCBI lists DAO and DAO1 among its historical or alternative names. Its encoded protein metabolizes histamine and related compounds.
DAO histamine gene & AOC1 variants
DAO Histamine Gene (AOC1): Variants & Histamine Breakdown
When people search for the DAO histamine gene, they are usually referring to AOC1, the gene that encodes the diamine oxidase enzyme commonly called DAO. This enzyme can metabolize histamine and other related amines.
AOC1 variants can provide inherited genetic context, but a DNA result does not directly measure your current DAO enzyme activity and does not diagnose histamine intolerance. The exact variant, supporting evidence and wider clinical context all matter.
- The histamine-related gene is AOC1
- DAO is the common name of the encoded enzyme
- Histamine is one of its substrates
- A genetic variant is not an enzyme-activity test
Official gene
AOC1 — amine oxidase copper containing 1
Common enzyme name
Diamine oxidase, often shortened to DAO
Relevant function
Metabolism of histamine and related amines
Key limitation
DNA does not directly measure current DAO activity
Quick answer
What Is the DAO Histamine Gene?
The gene most people mean by the “DAO histamine gene” is AOC1. AOC1 contains the inherited DNA instructions for amine oxidase copper containing 1, a protein commonly referred to as diamine oxidase.
The encoded enzyme can oxidatively metabolize histamine as well as other related compounds. That is why AOC1 appears frequently in discussions about genetic differences in histamine handling.
Plain-English answer: AOC1 is the gene; DAO is the common name of the histamine-metabolizing enzyme it encodes. A genetic result can tell you which AOC1 variant was detected, but it cannot by itself tell you exactly how much DAO enzyme is active in your body today.
Important terminology
Is DAO the Gene Name or the Enzyme Name?
This is an important distinction because two different human genes can appear when someone searches for “DAO gene.”
DAO is also the official symbol of the human D-amino acid oxidase gene. That gene is involved in D-amino-acid metabolism and should not be confused with AOC1 when researching diamine oxidase and histamine.
SEO and interpretation shortcut: If you are researching “DAO gene histamine,” “DAO histamine gene,” “DAO deficiency gene” or “histamine intolerance gene,” the relevant genetic entity is generally AOC1.
Histamine metabolism
What Does DAO Do With Histamine?
Diamine oxidase is an amine-metabolizing enzyme. Histamine is one of the compounds that the AOC1-encoded enzyme can break down through oxidative deamination.
That biological role is why AOC1 is frequently researched by people interested in histamine metabolism. However, the body handles histamine through more than one biological process, so AOC1 should not be treated as the sole explanation for every histamine-related question.
If your interest started with broader genetic testing, you can also explore the genetic pathway library or learn more about genetic intolerances and sensitivities.
Simple pathway view
How AOC1 Genetics Relates to DAO and Histamine
Keeping the gene, enzyme and biological function separate makes genetic results easier to understand.
AOC1 Gene
Your inherited DNA sequence
DAO Protein
Diamine oxidase encoded by AOC1
Histamine
One substrate that DAO can metabolize
Breakdown Products
Products formed through enzymatic metabolism
Important: A genetic test examines the first box—your DNA. It does not directly measure the amount or activity of DAO enzyme in the second box at the moment you take the test.
Variant interpretation
What Can an AOC1 or DAO Genetic Variant Tell You?
A genetic variant identifies a difference in the DNA sequence at a specific location. Some AOC1 variants have been studied in relation to DAO enzyme activity, but their meaning should be interpreted variant by variant.
What an AOC1 Genetic Result Can Provide
- The specific AOC1 variant detected by the test.
- Your inherited genotype at that tested location.
- Research context associated with that particular variant.
- A starting point for understanding DAO-related genetics.
What It Does Not Automatically Establish
- Your current DAO enzyme activity.
- Your current blood or tissue histamine level.
- A diagnosis of histamine intolerance.
- The cause of digestive, skin, respiratory or neurological symptoms.
- A requirement for dietary restriction or supplementation.
AEO answer: An AOC1 variant can provide genetic context about diamine oxidase, but genotype alone cannot confirm DAO deficiency or histamine intolerance.
DAO & histamine intolerance
Does an AOC1 Variant Mean You Have Histamine Intolerance?
No. Finding an AOC1 variant is not the same as diagnosing histamine intolerance.
Research has examined several AOC1 variants in people reporting histamine-related symptoms and has found relationships with DAO activity in some settings. However, genetic variants alone have not consistently separated symptomatic individuals from healthy controls, and genotype does not perfectly predict measured DAO activity.
AOC1 Variant
Shows inherited sequence information at a specific genetic location.
DAO Activity
Refers to enzyme function. This is a different type of information from a DNA genotype.
Symptoms & Evaluation
Symptoms can have many possible causes and require appropriate clinical evaluation rather than interpretation from a single SNP.
Methylation context
Is AOC1 a Methylation Gene?
AOC1 is better described as a gene involved in amine and histamine metabolism rather than as a core enzyme of the methylation cycle.
It may appear in broader genetic wellness reports alongside methylation-related genes, but its primary biological role should not be confused with genes directly involved in folate, methionine or one-carbon metabolism.
Avoid overinterpretation
Why One DAO SNP Cannot Explain Every Histamine Symptom
Genetic reports are most useful when they separate established evidence from assumptions. A single AOC1 SNP cannot tell you everything about DAO production, enzyme activity, diet or symptoms.
Differences in current biology can reflect many influences beyond one inherited variant. For that reason, a responsible genetic report should identify the exact variant and explain the limitations of interpreting it.
- Check the exact variant. Do not interpret “AOC1 positive” or “DAO mutation” without knowing which DNA location was tested.
- Separate DNA from enzyme activity. Genotype and current DAO function are not interchangeable.
- Do not self-diagnose from a SNP. Histamine-related symptoms can overlap with many other conditions.
- Avoid automatic diet conclusions. A genetic result alone does not establish that you need a low-histamine or other restrictive diet.
Genetic testing
What Should a DAO or AOC1 Genetic Report Explain?
If AOC1 appears in a broader genetic report, useful interpretation should go beyond simply marking the variant as “good” or “bad.”
The Exact Variant
The report should identify the specific genetic location being interpreted.
What Research Supports
Interpretation should reflect the quality and limits of evidence associated with that particular variant.
Gene-to-Enzyme Context
The report should distinguish AOC1 genetic information from measured DAO enzyme activity.
What It Cannot Diagnose
Results should not present one inherited variant as proof of a medical condition or treatment need.
For U.S. customers
DAO and AOC1 Genetic Testing in the USA
If you are researching at-home genetic testing in the United States, first confirm what the test actually measures. A consumer DNA report provides inherited genetic information; it is not the same as a clinical test of current histamine levels or DAO enzyme activity.
Check Test Scope
Confirm whether AOC1 is included and which variant or variants are analyzed rather than assuming every broad DNA panel covers the same information.
Review the Report First
Use available sample results to understand how variants and limitations are presented before choosing a test.
Review Privacy & Availability
Before providing a DNA sample, review current testing availability, shipping information and the provider's genetic-data and privacy terms.
Broader genetic context
Explore Other Genes and Pathways
AOC1 answers a different biological question from many genes associated with methylation. Explore related genetic guides without treating all of them as part of one single pathway.
MTHFR
Learn about MTHFR and its role in folate-related one-carbon metabolism.
COMT
Explore COMT genetic context and how this enzyme fits into broader metabolic discussions.
MTR
Understand MTR's connection with methionine, homocysteine and vitamin B12-related metabolism.
Gene Library
Browse additional genetic guides and understand each gene within its appropriate biological pathway.
Evidence & terminology
How We Interpret the DAO Histamine Gene
This page uses AOC1 as the official gene name and uses DAO when referring to diamine oxidase or the terminology commonly used by people researching histamine genetics. This avoids confusing AOC1 with the separate human DAO gene that encodes D-amino acid oxidase.
Official gene identity
NCBI identifies AOC1 as amine oxidase copper containing 1 and
lists DAO and DAO1 among its alternative names.
Interpretation guardrail
Genetic variation and measured DAO enzyme activity are different
types of biological information and should not be treated as
interchangeable.
Last reviewed
August 20, 2026. Gene nomenclature, evidence and product
information should be reviewed periodically.
Scientific references: NCBI Gene — AOC1 , NCBI Gene — DAO and research on AOC1 variants and DAO activity .
DAO histamine gene FAQ
Frequently Asked Questions About AOC1, DAO and Histamine
Clear answers to common questions about the DAO histamine gene, AOC1 variants, histamine metabolism and genetic testing.
What is the DAO histamine gene?
The gene commonly meant by “DAO histamine gene” is AOC1. AOC1 encodes amine oxidase copper containing 1, commonly known as diamine oxidase or DAO, an enzyme that can metabolize histamine and related compounds.
Is the DAO gene actually called AOC1?
For histamine-related diamine oxidase, yes: AOC1 is the official gene symbol. DAO and DAO1 are alternative names historically associated with AOC1. However, DAO is also the official symbol of a separate D-amino acid oxidase gene.
What does DAO do to histamine?
Diamine oxidase can metabolize histamine through oxidative deamination. Histamine is one of several compounds that the AOC1-encoded enzyme can process.
Can an AOC1 variant diagnose histamine intolerance?
No. An AOC1 genetic result provides inherited DNA information, but carrying a variant does not by itself diagnose histamine intolerance or prove reduced DAO enzyme activity.
Does a DAO genetic test measure DAO enzyme activity?
No. A genetic test identifies DNA variants. Current enzyme activity is a different biological measurement and cannot be assumed directly from genotype alone.
Is DAO a methylation gene?
AOC1 is more accurately described as an amine- and histamine-metabolism gene. It may appear in broader genetic wellness reports, but it is not a core enzyme of the folate or methionine methylation cycle.
Does an AOC1 variant mean I need a low-histamine diet?
No. A genetic variant alone does not establish the need for a restrictive diet. Dietary decisions should consider symptoms, nutritional needs and appropriate professional evaluation rather than one SNP result.
What should I look for in an AOC1 genetic report?
Look for the exact variant tested, a clear explanation of the available evidence, gene-to-enzyme context and explicit limitations about what the result cannot diagnose or directly measure.
Important health information:
This page provides educational information about AOC1 genetics,
diamine oxidase and histamine metabolism. A consumer genetic result
does not diagnose histamine intolerance, allergy, DAO deficiency or
another medical condition and does not directly measure current
histamine or DAO enzyme activity. Persistent or significant symptoms
should be evaluated by a qualified healthcare professional.
Understand the wider genetic picture
Explore Genetic Results Beyond a Single DAO Variant
AOC1 can provide useful inherited context about diamine oxidase, but one SNP should not be treated as a complete explanation of histamine metabolism. Review the report structure, understand the limitations and compare broader genetic information before choosing a test.
Use genetic information as context—not as a stand-alone diagnosis or treatment plan.