Wet Macular Degeneration Risk and Your Genetics

What is wet macular degeneration risk?

Wet macular degeneration is a form of age-related macular degeneration (AMD) characterized by the abnormal growth of new blood vessels beneath the retina. These vessels, known as choroidal neovascularization (CNV), are fragile, prone to leaking fluid and blood, and can cause rapid central vision loss. Wet AMD progresses more quickly than dry AMD, but it is also the most treatable form when identified early.

Research base: Robust.

Wet AMD affects millions of people worldwide and is a leading cause of vision loss among older adults. Unlike dry AMD, which involves gradual accumulation of cellular debris, wet AMD involves active vascular growth driven by signaling molecules — most notably VEGF (vascular endothelial growth factor). This distinction matters clinically: anti-VEGF therapies have transformed outcomes, with many patients maintaining or even recovering meaningful vision when treatment begins promptly.

Your ExomeDNA result for Wet Macular Degeneration Risk reflects common genetic variation across multiple regions of the genome that together shape how your biology navigates the complement immune system, choroidal tissue integrity, and the inflammatory environment of the macula.

The genetics behind wet macular degeneration risk

Wet AMD has one of the strongest genetic architectures of any common complex disease. Genome-wide association studies have identified dozens of contributing loci, with two chromosomal regions — the complement factor H (CFH) region on chromosome 1q32 and the 10q26 locus — accounting for a substantial portion of inherited risk.

CD46 and complement regulation on neovascular vessels

The central biological narrative for wet AMD risk involves the complement immune system — a cascade of proteins that eliminates pathogens and clears cellular debris. CD46 (membrane cofactor protein) is a regulatory protein expressed on the surface of virtually all nucleated human cells, including the vascular endothelial cells that line blood vessels. Its role is to serve as a cofactor for complement factor I (CFI) in inactivating C3b and C4b at the cell surface — effectively signaling "do not attack" to prevent complement-mediated damage to healthy tissue.

In wet AMD, this regulatory function becomes critically relevant. When choroidal neovascularization occurs, new, fragile blood vessels grow from the choroid into the subretinal space. These vessels express CD46, but in the highly inflammatory complement environment that characterizes advanced AMD, the regulatory capacity of CD46 may be overwhelmed. Genetic variants associated with reduced CD46 regulatory efficiency may allow complement-mediated inflammation to damage the endothelium at the leading edge of these neovascular membranes, accelerating vessel leakage and tissue disruption.

The 10q26 locus: ARMS2 and PLEKHA1

The 10q26 chromosomal locus is one of the two most replicated regions in all of AMD genetics. ARMS2 encodes a small primate-specific protein that localizes to the choroidal extracellular matrix — the structural scaffolding between the retinal pigment epithelium (RPE) and the choroidal blood vessels. Variants in ARMS2 are among the most strongly associated signals for neovascular AMD specifically, and the protein's location at the RPE-choroid interface suggests a role in how this tissue layer responds to oxidative and inflammatory stress.

PLEKHA1, located adjacent to ARMS2 at 10q26, encodes a pleckstrin homology domain-containing protein and appears consistently in wet AMD association studies. Given the tight genomic proximity and high linkage disequilibrium in this region, PLEKHA1 and ARMS2 are studied together as part of a shared locus with strong neovascular AMD association.

Complement pathway: CFH, CFI, and C3

CFH (complement factor H) is the principal soluble inhibitor of the alternative complement pathway and is produced in the liver as well as locally in the retina. Variants in CFH represent the single largest common genetic contributor to AMD overall. CFI (complement factor I) works in concert with membrane cofactors like CD46 to inactivate C3b, preventing runaway complement amplification. C3 sits at the convergence point of all three complement activation pathways — classical, lectin, and alternative. Together, dysregulation across CFH, CFI, CD46, and C3 can produce the chronic low-grade complement activation in the macula that is thought to promote VEGF secretion by stressed RPE cells, driving neovascular conversion.

CETP and lipid biology

CETP (cholesteryl ester transfer protein) is involved in reverse cholesterol transport and lipid metabolism. Lipid accumulation in Bruch's membrane — the thin layer between the RPE and the choroid — is a key feature of AMD pathology. Variants in CETP have been associated with AMD risk in large-scale genomic studies, connecting vascular lipid biology to the choroidal environment.

SKIC2

SKIC2 encodes an RNA helicase involved in RNA surveillance and quality control. Its emergence as a GWAS locus in AMD biology represents an area of active investigation; the mechanistic connection to choroidal or complement biology has not yet been fully characterized.

Key loci: The CFH region and the 10q26 locus (ARMS2/PLEKHA1) together account for an estimated 50–60% of the genetic variance in AMD susceptibility in European-ancestry populations, making AMD among the most heritable common diseases studied.

What the research says

A large-scale genomic study published in Science in 2024 — drawing on the VA Million Veteran Program, one of the most expansive and diverse biobank efforts ever conducted — examined the genetic architecture of over 2,000 traits across a multi-ancestry population of U.S. veterans (Verma A et al., 2024, PMID 39024449). This study confirmed and extended known AMD associations, including signals at complement-related loci, and identified cross-ancestry patterns in AMD genetic architecture.

The Million Veteran Program cohort is particularly valuable because it includes substantial representation from African American, Hispanic, and Asian American participants alongside European American participants — enabling researchers to assess whether genetic risk signals replicate across ancestries and to fine-map causal variants with greater precision.

Scale: The VA Million Veteran Program study (Verma A et al., 2024) analyzed genetic data from over one million participants — among the largest human genomic studies ever conducted — examining 2,068 traits simultaneously to characterize shared and distinct genetic architectures.

The broader AMD genetics literature, of which this study is one component, has established that wet AMD specifically carries strong genetic loading at complement and 10q26 loci, and that genetic risk scores can meaningfully stratify individuals by their likelihood of neovascular progression.

How wet macular degeneration risk affects you

Understanding your genetic risk for wet AMD is most useful in the context of what it means for monitoring and early detection — because the defining feature of wet AMD is that it is highly treatable when caught early.

Why wet AMD is different from dry AMD

In dry AMD, cellular debris called drusen accumulates gradually beneath the retinal pigment epithelium, and central vision loss (if it occurs) tends to develop over years to decades. Wet AMD involves active vascular biology: VEGF released by hypoxic or stressed RPE cells stimulates the growth of new blood vessels from the choroid into the subretinal space. These vessels are abnormal — they lack the tight junctions of healthy retinal vasculature — and they leak fluid and blood into the space beneath the retina, distorting the photoreceptors that provide sharp central vision.

The result is that wet AMD can progress from first symptoms to significant central vision loss in weeks to months without treatment. However, this same biological mechanism — VEGF-driven neovascularization — is precisely what anti-VEGF therapies target. Drugs such as ranibizumab, aflibercept, bevacizumab, and faricimab are injected directly into the vitreous of the eye and block VEGF signaling, causing the abnormal vessels to regress and fluid to reabsorb. When initiated promptly, anti-VEGF therapy can stabilize or improve vision in the majority of treated eyes.

Conversion from dry to wet

Most people with wet AMD first have dry AMD, and a subset convert to the neovascular form over time. The complement cascade is thought to play a central role in this transition: chronic complement-mediated inflammation in the macula creates a microenvironment that upregulates VEGF production, eventually crossing a threshold that triggers CNV. Genetic variants that reduce complement regulation efficiency — including variants near CFH, CFI, CD46, and C3 — may increase the probability of this conversion.

Practical implications

A genetic result indicating elevated wet AMD risk is not a prediction that wet AMD will develop. It reflects polygenic background that, in aggregate across population studies, associates with higher average likelihood. Many people with elevated polygenic risk never develop AMD. The value is in informing the intensity and frequency of eye monitoring, particularly as you approach ages where AMD risk rises (typically 50+).

Working with your wet macular degeneration risk result

The most important action anyone can take in response to AMD risk information — genetic or otherwise — is to establish regular ophthalmologic monitoring and to know the early warning signs that require urgent evaluation.

Daily Amsler grid monitoring

The Amsler grid is a simple visual test — a grid of horizontal and vertical lines with a central fixation dot — that detects distortion or blind spots in central vision. Any new waviness, blurring, or missing areas on the Amsler grid should prompt an urgent ophthalmology visit, not a routine scheduled appointment. Home monitoring devices (such as the ForeseeHome monitor) are available for higher-risk individuals and can detect subtle changes between clinical visits.

Anti-VEGF therapy: the treatment landscape

If wet AMD is identified, anti-VEGF injections are the standard of care and are effective. Treatment typically involves monthly injections initially, followed by a maintenance schedule based on individual response. Many patients achieve stable or improved vision outcomes. The key determinant of long-term visual prognosis is how quickly treatment begins after CNV onset.

Modifiable risk factors

Smoking is the single most impactful modifiable risk factor for AMD overall, including wet AMD — it roughly doubles the risk and accelerates disease progression. Cessation at any age reduces risk trajectory. UV protection (quality sunglasses), a diet rich in leafy green vegetables and omega-3 fatty acids, and blood pressure management support overall retinal vascular health. AREDS2 supplementation (vitamins C and E, lutein, zeaxanthin, zinc) has evidence supporting a protective effect for individuals with intermediate AMD.

Discussing results with a clinician

Your ExomeDNA genetic result is a starting point for a conversation with an ophthalmologist or optometrist — not a clinical finding. A clinician can integrate your genetic background with retinal imaging (OCT, fundus photography) and personal and family history to determine the appropriate monitoring schedule for you.

Wet AMD shares genetic architecture with other traits related to complement function, retinal health, and cardiovascular biology. Exploring these related areas can provide a more complete picture of how interconnected these biological systems are.

Dry Macular Degeneration Risk (/trait/dry-macular-degeneration-risk): The dry form of AMD shares many of the same genetic loci — particularly at CFH and 10q26 — but involves different downstream biology. Many cases of wet AMD begin as dry AMD.
Macular Degeneration Risk (/trait/macular-degeneration-risk): An aggregate view of AMD risk that captures both neovascular and atrophic forms.
Glaucoma Risk (/trait/glaucoma-risk): A distinct eye condition with some shared genetic pathways and overlapping environmental risk factors.
Inflammatory Response (/trait/inflammatory-response): Complement dysregulation is fundamentally inflammatory. Variants near CFH, C3, and CD46 connect AMD biology to systemic inflammatory response profiles.
Cardiovascular Health Score (/trait/cardiovascular-health-score): CETP-linked lipid biology and vascular health intersect with AMD pathology at the level of Bruch's membrane lipid accumulation and choroidal vascular health.
CFH Gene Page (/gene/cfh): Complement factor H is the most studied single gene in AMD genetics. The CFH gene page provides a detailed look at its biology and the variants most associated with AMD risk.

Frequently asked questions

Q: What is the difference between wet AMD and dry AMD genetically? A: Both forms share major genetic signals — particularly at CFH and the 10q26 locus containing ARMS2 and PLEKHA1. However, wet AMD (neovascular AMD) tends to have stronger associations with complement regulatory genes such as CD46 and CFI, which influence how well the body controls complement activity on the surfaces of blood vessel cells. Dry AMD is more strongly associated with atrophic degeneration of the RPE without vascular involvement. In practice, the same polygenic risk score captures risk for both forms, but specific variants may shift the probability toward neovascular conversion.

Q: Is wet AMD hereditary? A: There is a significant hereditary component to AMD overall, and wet AMD in particular has a strong genetic architecture. Having a first-degree relative with AMD meaningfully increases your own risk. However, AMD is a complex polygenic disease — many genetic variants each contribute a small amount to risk, and environmental factors, particularly smoking, also play a major role. Having a genetic predisposition does not guarantee development of wet AMD, and the absence of family history does not eliminate risk.

Q: How does CD46 relate to wet AMD specifically? A: CD46 is a complement regulatory protein expressed on the surface of virtually all nucleated cells, including the endothelial cells that line blood vessels. In wet AMD, abnormal blood vessels grow into the subretinal space (a process called choroidal neovascularization). These vessels need to regulate complement activity on their surface to avoid immune-mediated damage. CD46 helps do this by inactivating complement fragments C3b and C4b. When genetic variants reduce CD46's regulatory efficiency, the highly inflammatory environment of advanced AMD may be sufficient to cause complement-mediated damage at the leading edge of these new vessels, worsening the neovascular process.

Q: Can anti-VEGF treatment reverse vision loss from wet AMD? A: Anti-VEGF therapies — including drugs such as ranibizumab, aflibercept, and faricimab — are highly effective at halting the progression of wet AMD and in many cases can improve vision by reducing fluid accumulation and allowing the retina to recover. The probability of meaningful visual recovery is highest when treatment begins early, before significant photoreceptor damage has occurred. This is why monitoring for early symptoms — such as new visual distortion on the Amsler grid — is so important for anyone at elevated risk.

Q: What practical steps should someone with elevated wet AMD genetic risk take? A: The highest-yield actions are: (1) establish regular eye examinations with an ophthalmologist, who can perform retinal imaging to detect early AMD changes; (2) monitor daily with an Amsler grid and treat any new distortion as an urgent concern; (3) stop smoking if you currently smoke — this is the single largest modifiable risk factor; (4) protect eyes from UV exposure; and (5) discuss whether AREDS2 supplementation is appropriate if early AMD signs are already present. Your genetic result can help motivate these steps and inform how aggressively to pursue monitoring.

By the ExomeDNA Research Team

This page contains general information only. For personal health decisions, consult a qualified clinician.

References

Verma A et al. (2024). Diversity and scale: Genetic architecture of 2068 traits in the VA Million Veteran Program. Science. PMID: 39024449. DOI: 10.1126/science.adj1182

Data sources: Genetic associations identified through genome-wide association analyses across large population biobanks.

ExomeDNA genetic results are for wellness and educational purposes only. Consult a clinician for personalized health guidance. Genetic results do not substitute for professional clinical evaluation.

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