Methylation & Detox

Catalase promoter variant affecting hydrogen peroxide clearance and antioxidants defense capacity

DAO structural variant affecting enzyme activity and histamine degradation

Missense variant in methionine synthase reductase that impairs B12 reactivation, elevating homocysteine and reducing methylation capacity

Phase I detoxification enzyme that activates polycyclic aromatic hydrocarbons and metabolizes estrogens; the Val variant increases catalytic activity, producing more reactive intermediates

Missense variant in the diamine oxidase enzyme that contributes to reduced histamine clearance from dietary sources

Selenium-dependent antioxidant enzyme that neutralizes hydrogen peroxide; the Leu variant reduces enzyme activity and responsiveness to selenium

Folate transporter — how well folate gets into your cells

Deep intronic MTR variant associated with reduced cleft lip/palate risk via lower methionine synthase expression

Deep intronic MTR variant associated with reduced cleft lip/palate risk via lower methionine synthase expression

Intronic MTR variant associated with neural tube defect risk

Second functional variant in glutathione S-transferase Pi 1, reducing enzyme activity to ~80% of normal and defining key GSTP1 haplotypes that affect detoxification capacity and cancer susceptibility

Promoter variant that increases GGH expression, accelerating hydrolysis of intracellular folate polyglutamates and reducing cellular folate retention

HNMT structural variant - reduces enzyme stability and histamine clearance in tissues

Intronic variant in the cytoplasmic trifunctional folate enzyme MTHFD1, associated with increased risk of congenital heart defects and neural tube defects — particularly under low dietary folate conditions

Intronic variant in the de novo DNA methyltransferase DNMT3A, associated with altered stress-response methylation patterns and immune cell ratios

NAT2 acetylation speed tag SNP - marks rapid vs slow acetylator haplotypes

Missense variant in methionine synthase reductase that raises homocysteine when vitamin B12 is low, affecting B12-dependent methylation efficiency

Vitamin D receptor — affects how well vitamin D activates cellular processes

Intronic MTRR tag SNP in a haplotype block where the C-allele variant associates with attenuated colorectal cancer survival benefit, modulated by pre-diagnostic alcohol intake

Phase II detoxification enzyme that conjugates glutathione to carcinogens, drugs, and oxidative stress products; this variant alters the active site geometry, changing substrate specificity

Slow acetylator variant affecting Phase II detoxification capacity

Nitric oxide production - reduced activity increases cardiovascular risk and oxidative stress

Phase II detoxification enzyme that reduces quinones and recycles CoQ10 to its active ubiquinol form; variant causes near-complete loss of enzyme activity

Signal-peptide missense variant; C allele carriers show modestly lower plasma homocysteine

Key enzyme for converting folate to its active methylfolate form

A synonymous variant in CBS affecting homocysteine metabolism and associated with modest changes in transsulfuration pathway activity

Phase II detoxification - acetylation of aromatic amines and certain medications

B12 recycling enzyme — regenerates active B12 for the methylation cycle

Synonymous MTRR variant (c.1911G>A) associated with congenital heart disease risk in offspring and maternal carriers

Methionine synthase — uses B12 to convert homocysteine to methionine

Intronic NOS3 variant associated with ankle-brachial index and peripheral arterial disease risk in hypertensive adults; G allele linked to lower peripheral blood flow

Alters one-carbon metabolism and folate distribution; influences cancer risk and folate levels

Reduces intestinal folate hydrolase activity, impairing absorption of dietary polyglutamyl folates and lowering circulating folate available for methylation

Histamine breakdown in gut - reduced activity means dietary histamine accumulates

NOS3 expression - controls how much eNOS enzyme is produced for nitric oxide synthesis

Folate processing enzyme — reduced stability increases choline need

Intronic MTR variant associated with B12-dependent methylation stress

Common synonymous variant in the CBS gene

Tag SNP proxy for GSTM1 gene deletion status — the most common pharmacogenomic variant worldwide, eliminating a Phase II detoxification enzyme that conjugates glutathione to environmental carcinogens

Missense variant in betaine-homocysteine methyltransferase that reduces enzyme throughput and influences homocysteine, betaine, and choline metabolite levels

Intronic MTRR variant with sex-specific association with DNA methylation patterning in one-carbon metabolism

Intronic marker in the folate transporter gene

Missense/splicing variant in sepiapterin reductase that reduces BH4 biosynthesis to ~15% of normal, impairing dopamine and serotonin production; causes dopa-responsive dystonia in biallelic carriers

Dopamine/catecholamine breakdown — affects stress response and methyl donor tolerance

Primary mitochondrial antioxidant enzyme - variant reduces superoxide detoxification in mitochondria

Lactase persistence - ability to digest lactose (milk sugar) in adulthood

Intronic variant in betaine-homocysteine methyltransferase gene associated with selenium levels but no known disease risk

Reduces intestinal GCPII enzyme activity by 53%, paradoxically raising circulating folate

Phosphatidylcholine production — affects dietary choline requirements

Intronic variant in the mitochondrial folate enzyme MTHFD2, influencing one-carbon metabolism and linked to folate receptor autoantibody levels and embryonic development risk

Intronic NOS3 variant that alters splicing factor binding and is associated with blood pressure and cardiovascular risk, with effects that are amplified by physical activity