What you carry at this position in your DNA and what research says about it.
Macular Degeneration Risk: 9/10 evidence, 58 publications.
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Sample genotype (not yours): C/C
High Risk of Macular Degeneration
Two copies of the C allele significantly increase the risk of age-related macular degeneration (AMD). This genetic profile is also associated with a poorer response to certain standard eye treatments.
What this genotype means: Significantly higher risk of age-related macular degeneration; Poorer response to anti-VEGF eye treatments; Altered complement factor H protein function.
Sample genotype (not yours): C/T
Moderate Risk of Macular Degeneration
One copy of the C allele is associated with a moderately increased risk of age-related macular degeneration. This profile may also slightly affect response to certain eye therapies.
What this genotype means: Moderately increased risk of age-related macular degeneration; Potentially reduced response to certain eye therapies; Slightly altered retinal inflammatory response.
Sample genotype (not yours): T/T
Typical Risk of Macular Degeneration
Two copies of the T allele are associated with a lower risk of age-related macular degeneration. This profile is also linked to a better response to standard eye treatments.
What this genotype means: Lower risk of age-related macular degeneration; Optimal response to anti-VEGF eye treatments; Healthy regulation of complement-mediated inflammation.
Gene function and biological role
Gene Function: The CFH gene encodes complement factor H, a key regulatory protein of the body's innate immune system [1]. It specifically controls the alternative pathway of the complement system, preventing it from attacking healthy host tissues [1]. By binding to specific cell surface markers, complement factor H inactivates inflammatory cascades [1]. Proper function of this protein is vital for maintaining tissue homeostasis, particularly in the delicate layers of the retina [2]. Disruptions in this gene can lead to chronic, low-grade local inflammation and tissue damage [3].
Variant Impact: A missense mutation at rs1061170 changes the amino acid at position 402 of the complement factor H protein from tyrosine to histidine [4]. This specific amino acid substitution occurs within a critical binding domain of the protein [1]. The change significantly reduces the protein's ability to bind to cell surfaces and regulate complement activation [1]. As a result, individuals carrying the risk allele experience increased complement-mediated inflammation, especially in the eye [3]. This chronic inflammatory state is a primary driver of retinal damage and vision loss [5].
Key Insight: This variant is one of the strongest known genetic risk factors for age-related macular degeneration, explaining a significant portion of the disease's genetic liability. Interestingly, the same genetic change that increases eye disease risk also influences how well a person responds to standard injectable vision-saving therapies.
Location: CFH. Chromosome 1 · 1q31.3 · 196.7 Mb
Estimated prevalence by population
Global 13.2%; European 14.6%; African 13.8%; East Asian 0.3%; South Asian 7.8%; Americas 6.9%; Ashkenazi 11.5%; Finnish 19.1%; Middle Eastern 12.0%; Amish 23.2%.
Estimated CC genotype frequency.
Global 44.8%; European 47.2%; African 46.7%; East Asian 9.8%; South Asian 40.3%; Americas 38.7%; Ashkenazi 44.8%; Finnish 49.2%; Middle Eastern 45.3%; Amish 49.9%.
Estimated CT genotype frequency.
Global 42.1%; European 38.2%; African 39.5%; East Asian 90.0%; South Asian 51.8%; Americas 54.4%; Ashkenazi 43.7%; Finnish 31.7%; Middle Eastern 42.8%; Amish 26.9%.
Estimated TT genotype frequency.
Showing effects for C/C genotype
Organ Systems
Vision & Eye Health
Macular Degeneration. Evidence: 9/10. Source: PMID 20385826. ~5.9x Increased Risk.
Ranibizumab Response. Evidence: 6/10. Source: PMID 22840423. Poorer Response.
Pharmacogenomics
Chemotherapy Response
Bevacizumab Response. Evidence: 6/10. Source: PMID 23204795. Poorer Response.
Lifestyle, Fitness & Aging
Aging & Longevity
Lifespan. Evidence: 3/10. Source: PMID 22936692. Reduced Longevity.
Showing effects for C/T genotype
Macular Degeneration. Evidence: 9/10. Source: PMID 20385826. ~2.5x Increased Risk.
Ranibizumab Response. Evidence: 6/10. Source: PMID 22840423. Typical Response.
Bevacizumab Response. Evidence: 6/10. Source: PMID 23204795. Higher Tolerance.
Showing effects for T/T genotype
Macular Degeneration. Evidence: 9/10. Source: PMID 20385826. Typical Risk.
Ranibizumab Response. Evidence: 6/10. Source: PMID 22840423. Stronger Response.
Bevacizumab Response. Evidence: 6/10. Source: PMID 23204795. Typical Response.
Lifespan. Evidence: 3/10. Source: PMID 22936692. Typical Longevity.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
A major genetic risk factor for age-related macular degeneration (AMD) is represented by this profile, showing an estimated 5.9-fold increase in risk compared to the typical genotype [1]. The genetic change alters the complement factor H protein, replacing tyrosine with histidine at position 402, which impairs its ability to regulate inflammation on cell surfaces [2]. This chronic, uncontrolled inflammation leads to the accumulation of cellular debris called drusen in the retina, damaging central vision over time [3]. Additionally, individuals with this genotype often show a poorer response to anti-VEGF medications like ranibizumab and bevacizumab, which are used to treat the wet form of AMD [4]. Studies also suggest a link to higher mortality rates in very old age, possibly due to systemic inflammation [5].
Significantly higher risk of age-related macular degeneration; Poorer response to anti-VEGF eye treatments; Altered complement factor H protein function.
Sample genotype: CT (Heterozygous)
An estimated 2.5-fold increase in the risk of developing age-related macular degeneration (AMD) is linked to this single-copy profile [1]. The presence of one histidine-encoding allele at position 402 reduces the efficiency of complement factor H in controlling inflammation on retinal tissues [2]. Over time, this can contribute to the formation of drusen, which are characteristic yellow deposits under the retina that precede vision loss [3]. In clinical settings, individuals with this genotype may respond less strongly to anti-VEGF therapies like bevacizumab, so optimal results can be harder to achieve [4]. There is also a modest association with higher mortality in nonagenarians compared to those with two copies of the protective allele [5].
Moderately increased risk of age-related macular degeneration; Potentially reduced response to certain eye therapies; Slightly altered retinal inflammatory response.
Sample genotype: TT (Homozygous)
Representing the typical genetic profile, this combination carries two copies of the protective T allele which encodes tyrosine at position 402 of the complement factor H protein [1]. This form of the protein is highly efficient at binding to cell surfaces and regulating the complement system, preventing excessive inflammation in the eye [2]. Consequently, individuals with this genotype have a significantly lower risk of developing both dry and wet forms of age-related macular degeneration (AMD) [3]. If treatment for neovascular AMD is ever required, those with this genotype typically show a superior response to anti-VEGF medications such as ranibizumab [4]. Furthermore, long-term survival studies indicate that individuals with this genotype generally experience greater longevity compared to carriers of the C allele [5].
Lower risk of age-related macular degeneration; Optimal response to anti-VEGF eye treatments; Healthy regulation of complement-mediated inflammation.
Variants with shared genetic architecture
rs800292 · CFH Gene · Chr 1 · Macular Degeneration Risk
rs10737680 · CFH Gene · Chr 1 · Macular Degeneration Risk
rs6695321 · CFH Gene · Chr 1 · Macular Degeneration Risk
Screening of CRISPR/Cas base editors to target the AMD high-risk Y402H complement factor H variant.
Distribution of risk alleles in patients with age-related macular degeneration.
Can genetic associations change with age? CFH and age-related macular degeneration.
Content updated August 2026.
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