What you carry at this position in your DNA and what research says about it.
Macular Degeneration Risk: 5/10 evidence, 55 publications.
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Sample genotype (not yours): C/C
Typical Macular Degeneration Risk
Standard levels of VEGF protein support normal blood vessel growth. This genotype is associated with a typical risk of macular degeneration and altitude sickness.
What this genotype means: Typical risk of macular degeneration; Typical adaptation to high altitudes.
Sample genotype (not yours): C/T
Mixed Health and Eye Risks
Having one copy of the T allele lowers VEGF protein levels. This reduces the risk of rapid cancer progression but increases susceptibility to macular degeneration and altitude sickness.
What this genotype means: Increased risk of macular degeneration; Higher susceptibility to altitude sickness; Slower breast cancer progression.
Sample genotype (not yours): T/T
Higher Macular Degeneration Risk and Drug Sensitivity
Two copies of the T allele significantly lower VEGF protein levels. This profile is linked to higher risks of macular degeneration, altitude sickness, and poorer responses to specific cancer therapies.
What this genotype means: Increased risk of macular degeneration; Higher susceptibility to altitude sickness; Poorer response to bevacizumab and chemotherapy.
Gene function and biological role
Gene Function: The VEGFA gene provides instructions for making a protein called vascular endothelial growth factor A, which is a key regulator of blood vessel growth [1]. This protein plays a critical role in angiogenesis, the process by which new blood vessels form from existing ones [1]. It is essential for normal tissue growth, wound healing, and embryonic development [2]. However, overproduction of this protein can promote abnormal blood vessel growth in the eyes and feed the growth of solid tumors [3]. Conversely, insufficient levels can impair blood vessel maintenance and tissue repair [4].
Variant Impact: Located in the 3 prime untranslated region of the VEGFA gene, this variant alters a regulatory region that controls how much protein is produced [1]. The change from a C to a T allele disrupts a binding site for the AP-4 transcription factor, leading to decreased gene expression [5]. Consequently, individuals carrying the T allele tend to have significantly lower levels of circulating VEGF protein in their blood [1]. This reduction in VEGF levels can limit abnormal blood vessel growth, which influences both cancer progression and susceptibility to eye diseases [6].
Key Insight: This variant represents a major biological trade-off where lower VEGF levels can slow down cancer progression but simultaneously increase the risk of macular degeneration and altitude sickness.
Location: VEGFA. Chromosome 6 · 6p21.1 · 43.8 Mb
Estimated prevalence by population
Global 75.9%; European 73.7%; African 83.7%; East Asian 68.0%; South Asian 81.3%; Americas 67.8%; Ashkenazi 75.3%; Finnish 72.1%; Middle Eastern 73.5%; Amish 84.6%.
Estimated CC genotype frequency.
Global 22.3%; European 24.3%; African 15.6%; East Asian 28.9%; South Asian 17.7%; Americas 29.1%; Ashkenazi 22.9%; Finnish 25.6%; Middle Eastern 24.5%; Amish 14.8%.
Estimated CT genotype frequency.
Global 1.8%; European 2.0%; African 0.7%; East Asian 3.1%; South Asian 1.0%; Americas 3.1%; Ashkenazi 1.7%; Finnish 2.3%; Middle Eastern 2.0%; Amish 0.6%.
Estimated TT genotype frequency.
Showing effects for C/C genotype
Organ Systems
Vision & Eye Health
Macular Degeneration. Evidence: 4/10. Source: PMID 20847577. Typical Risk.
Lifestyle, Fitness & Aging
Stress Response & Resilience
Altitude Sickness. Evidence: 3/10. Source: PMID 21242666. Typical Risk.
Cancer & Oncology
Cancer Prognosis & Treatment Outcome
Breast Cancer Prognosis. Evidence: 3/10. Source: PMID 22315135. Typical Progression.
Immunity & Inflammation
Inflammatory & Circulating Protein Markers
VEGF-A Levels. Evidence: 5/10. Source: PMID 21982816. Typical Levels.
Pharmacogenomics
Drug Metabolism Enzyme Activity
Drug Response. Evidence: 5/10. Source: PMID 25955730. Typical Response.
Showing effects for C/T genotype
Macular Degeneration. Evidence: 4/10. Source: PMID 20847577. ~2.6x Increased Risk.
Altitude Sickness. Evidence: 3/10. Source: PMID 21242666. Increased Risk.
Breast Cancer Prognosis. Evidence: 3/10. Source: PMID 22315135. Slower Progression.
VEGF-A Levels. Evidence: 5/10. Source: PMID 21982816. Lower Levels.
Showing effects for T/T genotype
Drug Response. Evidence: 5/10. Source: PMID 25955730. Poorer Response.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Carrying two copies of the common C allele results in typical production of the VEGF protein [1]. This level of protein is sufficient for maintaining healthy blood vessel networks throughout the body [1]. However, standard VEGF levels also mean there is no genetic protection against rapid tumor angiogenesis in certain cancers [2]. Studies show that this genotype is associated with a baseline risk for age-related macular degeneration compared to T allele carriers [3]. It also correlates with a typical response to anti-VEGF therapies like bevacizumab [4]. Overall, this represents the most common genetic profile globally.
Typical risk of macular degeneration; Typical adaptation to high altitudes.
Sample genotype: CT (Heterozygous)
Carrying one copy of the T allele reduces the overall expression of the VEGF protein [1]. Lower VEGF levels can be beneficial in oncology, as they are linked to slower tumor blood vessel growth and delayed cancer progression [2]. However, this reduction can also have negative consequences for eye health, increasing the risk of age-related macular degeneration [3]. Research indicates that the T allele is associated with a higher susceptibility to acute mountain sickness due to altered blood vessel adaptation at high altitudes [4]. It may also slightly modify how the body responds to certain vascular-targeting medications [5]. This genotype represents a classic genetic trade-off between different health outcomes.
Increased risk of macular degeneration; Higher susceptibility to altitude sickness; Slower breast cancer progression.
Sample genotype: TT (Homozygous)
Carrying two copies of the T allele leads to the lowest levels of circulating VEGF protein [1]. While this can slow down the progression of certain cancers by limiting tumor blood supply, it significantly increases other health risks [2]. Specifically, this genotype is associated with an increased risk of age-related macular degeneration [3]. It also correlates with a higher susceptibility to acute mountain sickness when traveling to high elevations [4]. Furthermore, clinical studies have linked this genotype to poorer responses and decreased survival when treated with certain chemotherapies and anti-VEGF drugs like bevacizumab [5]. This combination of factors makes the genotype a notable marker for both eye health and personalized medicine.
Increased risk of macular degeneration; Higher susceptibility to altitude sickness; Poorer response to bevacizumab and chemotherapy.
Variants with shared genetic architecture
rs833061 · VEGFA Gene · Chr 6 · Blood and Joint Health
rs699947 · VEGFA Gene · Chr 6 · Thyroid Cancer Risk
rs1570360 · VEGFA Gene · Chr 6 · Blood Vessel Health
Contribution of VEGF polymorphisms to variation in VEGF serum levels in a healthy population.
Polymorphisms of hypoxia-related genes in subjects susceptible to acute mountain sickness.
Content updated August 2026.
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