AOC1 rs1049793: What Your Genotype Means
The rs1049793 variant is a genetic change located within the AOC1 gene, which provides instructions for making the diamine oxidase (DAO) enzyme. This variant is studied for its potential association with reduced DAO activity, which may influence how the body processes histamine from food.
What each genotype means
Typical histamine metabolism
This genotype represents the most common form of the AOC1 gene at this position. Research suggests individuals with this profile typically maintain standard diamine oxidase (DAO) enzyme activity levels for breaking down dietary histamine. If you experience symptoms of histamine intolerance, they may be related to other genetic or environmental factors rather than this specific variant.
Carried by approximately 33% of the population, based on a global minor allele frequency of 0.4215.
Reduced histamine clearance capacity
This genotype, sometimes referred to as the heterozygous state, is associated with a potential reduction in the efficiency of the DAO enzyme in clearing histamine from the gut. While this may contribute to a higher sensitivity to histamine-rich foods, it is only one of many factors influencing histamine metabolism. Please discuss any dietary concerns or persistent symptoms with your clinician or a registered dietitian.
This is a common genotype found in a significant portion of the population across various ancestries.
Lower histamine clearance capacity
This genotype is associated with the His645Asp (or His664Asp) variant, which research indicates may lead to decreased diamine oxidase (DAO) enzyme activity. Individuals with this profile might be more susceptible to histamine intolerance symptoms when consuming high-histamine foods. Because DAO function is influenced by multiple genes and environmental factors, please consult with your healthcare provider or pharmacist before making significant changes to your diet or medication regimen.
This genotype is observed in a substantial segment of the population, consistent with the reported minor allele frequency.
Understanding the rs1049793 Variant
The rs1049793 variant is a single nucleotide polymorphism (SNP) located in the AOC1 gene, which is situated on chromosome 7. In genetic terms, this variant involves a substitution where the nucleotide cytosine (C) is replaced by guanine (G). This specific change is often referred to in scientific literature as p.His664Asp. Because it is a non-synonymous variant, it results in an amino acid change within the protein structure, which researchers investigate to determine if it alters the function or stability of the resulting enzyme. Genetic variants like rs1049793 are common, and they are frequently analyzed alongside other variants in the same gene to understand the cumulative impact on biological processes. It is important to note that the presence of a variant does not automatically imply a functional deficit, as many genetic variations have little to no impact on overall health.
The Role of the AOC1 Gene and DAO Enzyme
The AOC1 gene encodes the enzyme diamine oxidase (DAO). This enzyme plays a critical role in the body by breaking down histamine, a compound found in many foods and also produced by gut bacteria. DAO is primarily active in the small intestine, where it acts as a gatekeeper, preventing excessive amounts of dietary histamine from entering the bloodstream. When DAO activity is reduced, individuals may experience difficulty metabolizing histamine, a condition sometimes referred to as histamine intolerance. Symptoms associated with this condition can be diverse, ranging from gastrointestinal distress and headaches to skin reactions. While the AOC1 gene is a primary focus for researchers studying histamine metabolism, it is only one piece of a complex puzzle that includes diet, gut microbiome health, and other enzymes like histamine N-methyltransferase (HNMT) that also regulate histamine levels throughout the body.
Research Associations and Evidence Strength
Research into the rs1049793 variant is categorized as having limited evidence regarding its clinical impact. While some studies suggest that variants in the AOC1 gene, including rs1049793, may be associated with lower DAO enzyme activity, the scientific community emphasizes that more research is needed to establish a definitive causal link to specific health conditions. Current studies often look at the cumulative effect of multiple AOC1 variants rather than focusing on one in isolation. Because histamine intolerance is a multifactorial condition, it is difficult to attribute symptoms solely to a single genetic marker. Consequently, while this variant is a subject of interest in pharmacogenomics and nutritional science, it is not currently used as a standalone diagnostic tool. The evidence remains mixed, and findings can vary significantly between different study populations and clinical settings.
Population Frequency
The rs1049793 variant is relatively common in human populations. According to available data, the Global Minor Allele Frequency (GMAF) is approximately 0.4215, indicating that the variant is present in a significant portion of the population. Frequency can vary by ancestry, and researchers often compare these frequencies to ensure that genetic studies are representative of diverse groups. In many studies, the distribution of this variant follows Hardy-Weinberg equilibrium, meaning it is a stable, inherited trait within the population.
What This Information Means for You
Knowing your genotype for rs1049793 provides insight into your genetic makeup, but it should not be used to self-diagnose or make significant changes to your health regimen. Genetic associations are statistical in nature and do not predict individual outcomes. If you suspect you have sensitivities to histamine-rich foods or are experiencing persistent symptoms, it is essential to consult with a healthcare professional or a registered dietitian. They can help you evaluate your symptoms, consider environmental and dietary factors, and determine if further clinical testing is appropriate. Never use genetic information to alter prescribed medications or dosing schedules without first discussing these changes with your clinician or pharmacist. Genetic testing is a tool for information, but it is most effective when interpreted within the context of your overall health history and under the guidance of a qualified medical expert.
How common is this variant?
The rs1049793 variant is common, with a global minor allele frequency of approximately 0.4215.
Frequently asked questions
Can I use this genetic test to diagnose histamine intolerance?
No, genetic testing for rs1049793 cannot diagnose histamine intolerance. Histamine intolerance is a complex condition that requires a clinical evaluation by a doctor, often involving symptom tracking and dietary assessments.
Does having the G allele mean I must avoid all histamine-rich foods?
Not necessarily. Genetic variants are only one factor in how your body processes histamine. You should consult with a healthcare provider or dietitian before making restrictive changes to your diet.
Are there supplements that can fix this genetic variant?
There is no way to 'fix' a genetic variant. While some people use DAO enzyme supplements to help manage symptoms, you should discuss the safety and necessity of any supplement with your doctor first.
Is rs1049793 the only variant that affects DAO activity?
No, there are several other variants in the AOC1 gene, such as rs10156191 and rs1049742, that are also studied for their potential impact on DAO enzyme function. Researchers often look at the combined effect of multiple variants.
Sources & further reading
Educational information only, last refreshed 9/29/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs1049793?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29