What you carry at this position in your DNA and what research says about it.
Heart and Lung Health: 8/10 evidence, 25 publications.
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Sample genotype (not yours): C/C
Typical Heart and Lung Risk
Standard genetic baseline characteristics apply here, showing typical risks for cardiovascular and respiratory conditions. The superoxide dismutase enzyme remains bound to tissues, providing standard localized antioxidant defense.
What this genotype means: Standard localized antioxidant protection in tissues; Typical baseline risk for heart and lung diseases.
Sample genotype (not yours): C/G
Lower Lung Risk but Higher Heart Risk
A unique genetic trade-off is present here, offering protection against lung diseases while slightly increasing the risk of ischemic heart disease. The altered enzyme distribution shifts antioxidant protection from tissues into the bloodstream.
What this genotype means: Significantly reduced risk of chronic obstructive pulmonary disease; Slightly increased risk of ischemic heart disease; Elevated levels of circulating antioxidants in the blood.
Sample genotype (not yours): G/G
A pronounced genetic trade-off maximizes respiratory protection while elevating cardiovascular risk. The antioxidant enzyme is almost entirely redirected from tissues into circulation.
What this genotype means: Strongly reduced risk of chronic obstructive pulmonary disease; Elevated risk of ischemic heart disease; Highly elevated levels of circulating antioxidants in the blood.
Gene function and biological role
Gene Function: The SOD3 gene encodes extracellular superoxide dismutase, a vital antioxidant enzyme that protects tissues from oxidative stress [1]. This enzyme is highly active in the lungs and blood vessels, where it neutralizes harmful free radicals [1]. By doing so, it helps maintain vascular health and prevents tissue inflammation [1]. Under normal conditions, the enzyme binds tightly to the extracellular matrix of these tissues via a specific heparin-binding domain [2]. This localized binding ensures that the antioxidant protection is concentrated exactly where oxidative damage is most likely to occur [2].
Variant Impact: An arginine-to-glycine amino acid substitution at position 213 alters the heparin-binding domain of the SOD3 enzyme [1]. This structural change significantly reduces the enzyme's ability to bind to tissue matrices in the lungs and blood vessels [1]. As a result, the enzyme is released into the bloodstream, leading to a dramatic ten-fold increase in plasma superoxide dismutase levels [2]. While this shift increases circulating antioxidant levels, it leaves the lung and vascular tissues with less localized protection [1]. Consequently, this single change creates a unique trade-off between cardiovascular and respiratory health [1].
Key Insight: This variant causes a paradoxical trade-off, protecting the lungs from disease while simultaneously increasing the risk of heart disease by shifting where an antioxidant enzyme is located.
Location: SOD3. Chromosome 4 · 4p15.2 · 24.8 Mb
Estimated prevalence by population
Global 97.5%; European 97.5%; African 99.2%; East Asian 95.6%; South Asian 88.5%; Americas 96.5%; Ashkenazi 97.3%; Finnish 97.1%; Middle Eastern 94.6%; Amish 100.0%.
Estimated CC genotype frequency.
Global 2.5%; European 2.4%; African 0.8%; East Asian 4.3%; South Asian 11.1%; Americas 3.5%; Ashkenazi 2.7%; Finnish 2.9%; Middle Eastern 5.3%; Amish 0.0%.
Estimated CG genotype frequency.
Global < 0.1%; European < 0.1%; African < 0.1%; East Asian < 0.1%; South Asian 0.4%; Americas < 0.1%; Ashkenazi < 0.1%; Finnish < 0.1%; Middle Eastern 0.1%; Amish 0.0%.
Estimated GG genotype frequency.
Showing effects for C/C genotype
Cardiovascular & Metabolic
Heart Disease
Coronary Artery Disease. Evidence: 3/10. Source: PMID 14662715. Typical Risk.
Organ Systems
Respiratory Health
Lung Disease. Evidence: 4/10. Source: PMID 25085920. Typical Risk.
Kidney Function & Disease
Kidney Function. Evidence: 8/10. Source: PMID 39927731. Typical.
Immunity & Inflammation
Inflammatory & Circulating Protein Markers
Plasma SOD3 Levels. Evidence: 6/10. Source: PMID 8034674. Typical.
Showing effects for C/G genotype
Coronary Artery Disease. Evidence: 3/10. Source: PMID 14662715. ~1.5x Higher Risk.
Lung Disease. Evidence: 4/10. Source: PMID 25085920. ~50% Lower Risk.
Kidney Function. Evidence: 8/10. Source: PMID 39927731. Slightly Lower.
Plasma SOD3 Levels. Evidence: 6/10. Source: PMID 8034674. ~10-fold Higher.
Showing effects for G/G genotype
Coronary Artery Disease. Evidence: 3/10. Source: PMID 14662715. Higher Risk.
Lung Disease. Evidence: 4/10. Source: PMID 25085920. Lower Risk.
Plasma SOD3 Levels. Evidence: 6/10. Source: PMID 8034674. Highly Elevated.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Possessing two copies of the common C allele ensures the superoxide dismutase enzyme binds normally to the extracellular matrix of the lungs and blood vessels [1]. This localized binding provides typical, healthy antioxidant protection directly within these tissues [1]. Consequently, there is no genetically elevated risk for ischemic heart disease from this variant [2]. However, this genotype also does not benefit from the reduced risk of lung diseases like chronic obstructive pulmonary disease (COPD) associated with the G allele [1]. Overall, health risks remain at the typical population baseline [2].
Standard localized antioxidant protection in tissues; Typical baseline risk for heart and lung diseases.
Sample genotype: CG (Heterozygous)
Presence of a single G allele alters the heparin-binding domain of the SOD3 enzyme, causing it to detach from tissues and enter the bloodstream [1]. This redistribution leads to a massive increase in circulating plasma antioxidant levels [2]. In the lungs, this shift is highly beneficial, reducing the risk of chronic obstructive pulmonary disease (COPD) by approximately half [1]. However, the loss of localized antioxidant protection in the blood vessels increases the risk of ischemic heart disease by about 1.5 times [3]. This creates a distinct biological trade-off where one organ system is protected at the expense of another [1].
Significantly reduced risk of chronic obstructive pulmonary disease; Slightly increased risk of ischemic heart disease; Elevated levels of circulating antioxidants in the blood.
Sample genotype: GG (Homozygous)
Inheriting two copies of the G allele redirects nearly all of the superoxide dismutase enzyme from the lung and vascular tissues into the bloodstream [1]. This results in exceptionally high levels of circulating plasma antioxidants [2]. This dramatic shift provides robust protection against alveolar lung diseases, significantly lowering the risk of conditions like COPD [1]. Conversely, the severe depletion of localized antioxidant defense in the blood vessels further elevates the risk of ischemic heart disease [3]. This genotype represents the most pronounced expression of this cardiopulmonary trade-off [1].
Strongly reduced risk of chronic obstructive pulmonary disease; Elevated risk of ischemic heart disease; Highly elevated levels of circulating antioxidants in the blood.
Variants with shared genetic architecture
rs699473 · SOD3 Gene · Chr 4 · Brain Tumor Risk
rs2536512 · SOD3 Gene · Chr 4 · Lung and Vascular Health
rs10857147 · FGF5 Gene · Chr 4 · Blood Pressure
Content updated August 2026.
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