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Gene & pathway reference · FROM DR. PURSER’S TEACHING

AOC1

Encodes diamine oxidase, an enzyme involved in breaking down histamine and other amines. DAO is used here as an enzyme nickname; it is also the official symbol of a different gene.

Based on teaching by Dan Purser, MD. How we prepare these guides

Updated Sep 23, 2026 · Educational reference

THE TEACHING CONNECTION

Histamine: making it, responding to it, clearing it

Histamine: making it, responding to it, clearing it

Dr. Purser’s genetics reference places AOC1 in the histamine-clearance part of the gut and immune story. The enzyme it encodes, diamine oxidase, helps break down histamine and related amines. That is a different job from HDC, which helps make histamine, or HRH1 and HRH2, which receive its signals.

Putting the pieces together

The reference discusses headaches, digestive upset and skin symptoms in its histamine section, along with food-trigger patterns, DAO enzyme products and clinician-selected antihistamines. These are topics to investigate in context, not a conclusion that every headache or food reaction comes from AOC1. A useful history includes the food, portion, timing, repeatability and medicines involved.

Where the VARS Triad and MTHFR Daily fit

If you are exploring homocysteine or cytokines, Dr. Purser may discuss MTHFR Daily and the VARS Triad: VARS Glutathione, VARS SOD, and VARS Catalase. He gives glutathione a central place in his approach to antioxidant support.

A gene result alone cannot tell you that you need these products or that they will treat a condition. Review your current results, medicines, goals, and tolerance with your clinician before choosing a product or dose.

A question to bring to your visit

Are my reactions reproducibly linked to meals, and are we evaluating histamine clearance, allergy, mast-cell disease or another digestive problem?

Reading your own results

Bring your original report, current results, health history, and medicines to your visit. This information can help you ask questions, but it cannot diagnose a condition or choose a supplement dose for you.

Variant lookup

These names can help you find an entry on your original genetic report. Seeing a name here does not tell you whether it affects your health or whether you need treatment.

Names you may see

DAO · Amine Oxidase, Copper Containing 1 · Diamine Oxidase