What you carry at this position in your DNA and what research says about it.
Macular Degeneration Risk: 7/10 evidence, 56 publications.
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Sample genotype (not yours): G/G
Typical Macular Degeneration Risk
Maintaining two copies of the common G allele is associated with standard baseline risk for age-related macular degeneration. The structural integrity of the retina remains protected by typical levels of HTRA1 enzyme activity.
What this genotype means: Typical baseline risk of age-related macular degeneration; Standard response to anti-VEGF eye therapies.
Sample genotype (not yours): A/A
~10x Higher Macular Degeneration Risk
Carrying two copies of the A allele is strongly associated with a significantly elevated risk of wet age-related macular degeneration. Elevated enzyme levels can severely compromise the structural barriers behind the retina.
What this genotype means: Up to tenfold increased risk of wet age-related macular degeneration; Potentially reduced response to bevacizumab eye therapy; Highly elevated risk of vision loss when combined with smoking.
Sample genotype (not yours): G/A
~2x Higher Macular Degeneration Risk
Carrying one copy of the A allele is linked to a roughly twofold increase in the risk of developing age-related macular degeneration. This change can lead to elevated enzyme levels that gradually weaken retinal support tissues.
What this genotype means: Approximately twofold increased risk of age-related macular degeneration; Elevated sensitivity to environmental risk factors like smoking.
Gene function and biological role
Gene Function: The HTRA1 gene encodes a high-temperature requirement serine protease A1 enzyme that plays a critical role in cellular quality control and extracellular matrix maintenance [1]. This enzyme regulates cell growth, blood vessel formation, and tissue remodeling by degrading specific proteins [1]. In the eye, the enzyme helps maintain the structural integrity of Bruch's membrane, a critical barrier layer behind the retina [2]. Proper regulation of this protein is essential for preventing abnormal blood vessel growth and tissue breakdown in the macula [2].
Variant Impact: The rs11200638 variant is a single-nucleotide change located in the promoter region of the HTRA1 gene [1]. This promoter change alters transcription factor binding sites, which can lead to increased production of the HTRA1 enzyme [1]. Excess enzyme activity is thought to degrade structural proteins in the eye, weakening the barrier behind the retina [2]. This structural weakness allows abnormal blood vessels to grow and leak, directly driving the progression of macular degeneration [2].
Key Insight: This variant in the HTRA1 promoter can increase enzyme levels, weakening the structural barrier behind the retina and allowing abnormal blood vessels to grow.
Location: HTRA1. Chromosome 10 · 10q26.13 · 122.5 Mb
Estimated prevalence by population
Global 58.8%; European 61.4%; African 58.6%; East Asian 33.2%; South Asian 46.8%; Americas 59.3%; Ashkenazi 62.7%; Finnish 58.6%; Middle Eastern 63.7%; Amish 58.2%.
Estimated GG genotype frequency.
Global 35.6%; European 33.9%; African 35.9%; East Asian 48.9%; South Asian 43.2%; Americas 35.4%; Ashkenazi 33.0%; Finnish 35.9%; Middle Eastern 32.3%; Amish 36.1%.
Estimated GA genotype frequency.
Global 5.7%; European 4.7%; African 5.5%; East Asian 18.0%; South Asian 10.0%; Americas 5.3%; Ashkenazi 4.3%; Finnish 5.5%; Middle Eastern 4.1%; Amish 5.6%.
Estimated AA genotype frequency.
Showing effects for G/G genotype
Organ Systems
Vision & Eye Health
Macular Degeneration. Evidence: 7/10. Source: PMID 17053108. Typical Risk.
Wet Macular Degeneration. Evidence: 7/10. Source: PMID 28703135. Typical Risk.
Bone, Joint & Connective Tissue Health
Spinal Disc Degeneration. Evidence: 3/10. Source: PMID 19798546. Typical Risk.
Pharmacogenomics
Chemotherapy Response
Bevacizumab Response. Evidence: 5/10. Source: PMID 22594510. Typical Response.
Showing effects for A/A genotype
Macular Degeneration. Evidence: 7/10. Source: PMID 17053108. ~8x to 10x Risk.
Wet Macular Degeneration. Evidence: 7/10. Source: PMID 28703135. ~10x Higher Risk.
Spinal Disc Degeneration. Evidence: 3/10. Source: PMID 19798546. Higher Risk.
Bevacizumab Response. Evidence: 5/10. Source: PMID 22594510. Poorer Response.
Showing effects for G/A genotype
Macular Degeneration. Evidence: 7/10. Source: PMID 17053108. ~2x Higher Risk.
Wet Macular Degeneration. Evidence: 7/10. Source: PMID 28703135. Increased Risk.
Spinal Disc Degeneration. Evidence: 3/10. Source: PMID 19798546. Increased Risk.
What this genotype means for the people who carry it
Sample genotype: GG (Homozygous)
Inheriting the G/G genotype means the promoter region of the HTRA1 gene functions at a normal, baseline level [1]. This typical activity prevents the overproduction of the HTRA1 serine protease enzyme in retinal tissues [1]. As a result, the structural proteins making up Bruch's membrane are not excessively degraded, preserving the vital barrier behind the retina [2]. Clinical studies consistently show that this genotype does not elevate the risk for either dry or wet forms of macular degeneration [2]. Furthermore, standard responses to common anti-VEGF eye therapies like bevacizumab are typically observed if treatment ever becomes necessary [3]. Maintaining a healthy lifestyle, avoiding smoking, and protecting eyes from UV light remain the primary ways to support long-term vision health.
Typical baseline risk of age-related macular degeneration; Standard response to anti-VEGF eye therapies.
Sample genotype: AA (Homozygous)
Inheriting two copies of the A allele leads to a substantial increase in HTRA1 promoter activity and enzyme production [1]. This excess protease activity heavily degrades the extracellular matrix and Bruch's membrane in the macula [1]. The resulting structural instability allows abnormal, fragile blood vessels to grow beneath the retina and leak fluid, a hallmark of wet macular degeneration [2]. Clinical studies have linked this homozygous genotype to a roughly ten-fold increase in the risk of developing the wet form of the disease [2]. Additionally, some evidence suggests that this genotype may be associated with a poorer response to certain anti-VEGF treatments like bevacizumab [3]. Avoiding smoking is particularly critical, as the combination of this genotype and smoking dramatically increases the overall risk of severe vision loss [4].
Up to tenfold increased risk of wet age-related macular degeneration; Potentially reduced response to bevacizumab eye therapy; Highly elevated risk of vision loss when combined with smoking.
Sample genotype: GA (Heterozygous)
Possessing one copy of the risk-associated A allele alters the promoter activity of the HTRA1 gene [1]. This genetic variation increases the expression of the HTRA1 protease enzyme, which can accelerate the breakdown of structural proteins in the eye [1]. Over time, this degradation weakens Bruch's membrane, making the retina more vulnerable to damage and vision loss [2]. Research indicates that this genotype roughly doubles the likelihood of developing age-related macular degeneration compared to the typical genotype [2]. The risk is further compounded by environmental factors, as smoking has been shown to dramatically multiply the likelihood of vision impairment in those with this variant [3]. Regular eye exams and proactive cardiovascular health habits are often recommended to help monitor and protect retinal health.
Approximately twofold increased risk of age-related macular degeneration; Elevated sensitivity to environmental risk factors like smoking.
Variants with shared genetic architecture
rs10490924 · ARMS2 Gene · Chr 10 · Macular Degeneration Risk
rs800292 · CFH Gene · Chr 1 · Macular Degeneration Risk
rs1061170 · CFH Gene · Chr 1 · Macular Degeneration Risk
A variant of the HTRA1 gene increases susceptibility to age-related macular degeneration.
HTRA1 promoter polymorphism in wet age-related macular degeneration.
Content updated August 2026.
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