THE PURSER WELLNESS ENCYCLOPEDIA

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Gene referenceSep 23, 2026

HLA-DQA1

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HLA-DQA1 contributes to an HLA-DQ protein that presents antigen fragments to CD4 T cells. HLA-DQ function depends on pairing with an HLA-DQB chain, so an isolated marker is not a complete HLA type. Also called: HLADQA1, Human Leukocyte Anti…

Gene referenceSep 23, 2026

HLA-DQA2

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HLA-DQA2 is part of the HLA class II region involved in immune recognition. It should not be treated as interchangeable with HLA-DQA1 or as a measurement of how well the immune system fights infections. Also called: HLADQA2, Human Leukocyte…

Gene referenceSep 23, 2026

HRH1

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HRH1 is the gene name for Histamine Receptor H1. Learn what a specific result could mean and what to ask about it. Also called: Histamine Receptor H1 Receiving the histamine signal The Purser genetics reference places HRH1 in the histamine-…

Gene referenceSep 23, 2026

HRH2

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…for Histamine Receptor H2. Learn what a specific result could mean and what to ask about it. Also called: Histamine Receptor H2 Histamine also connects to stomach acid Dr. Purser’s genetics reference connects HRH2 with histamine signaling a…

Gene referenceSep 23, 2026

IL21

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IL21 encodes a cytokine involved in regulating lymphocytes, including B-cell responses. It sits within an immune network that connects T-cell help, antibody responses and inflammatory activity. Also called: IL-21, Interleukin 21 A link betw…

Gene referenceSep 23, 2026

IL23R

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IL23R encodes part of the receptor that receives IL-23 signals. This connects the gene to the maintenance of Th17-related immune responses, which differ from the Th2 patterns discussed in allergy. Also called: IL-23R, Interleukin 23 Recepto…

Gene referenceSep 23, 2026

IL6

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IL6 encodes interleukin-6, a cytokine involved in immune responses and acute-phase signaling. It can appear in discussions of infection, chronic inflammation and metabolic health, with effects that depend on the context. Also called: IL-6, …

Gene referenceSep 23, 2026

KIT

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KIT encodes a receptor tyrosine kinase that responds to stem cell factor. It participates in blood-cell development and mast-cell biology, making the exact variant and testing context especially important. Also called: Kit Proto-Oncogene A …

Gene referenceSep 23, 2026

MAOA

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MAOA helps break down some chemical messengers. A gene result cannot predict a mood or behavior. Also called: MAO-A, Monoamine Oxidase A Neurotransmitter breakdown in context Dr. Purser places MAOA in the neurotransmitter-breakdown part of …

Gene referenceSep 23, 2026

MAOB

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MAOB encodes monoamine oxidase B, an enzyme involved in breaking down monoamine compounds, including dopamine. It does not simply build dopamine, and a DNA marker is not a neurotransmitter measurement. Also called: MAO-B, Monoamine Oxidase …

Gene referenceSep 23, 2026

MMP3

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MMP3 encodes matrix metalloproteinase 3, an enzyme involved in breaking down components of the extracellular matrix. Controlled remodeling is part of repair, while excess activity can accompany inflammatory tissue damage. Also called: Matri…

Gene referenceSep 23, 2026

MTHFR

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Makes an enzyme that helps produce a form of folate used in the processing of homocysteine. Common variants are different from rare variants that cause severe MTHFR deficiency. Also called: Methylenetetrahydrofolate Reductase, C677T, A1298C…

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