MYOC rs74315330: What Your Genotype Means
The rs74315330 variant is a specific genetic change in the MYOC gene, often referred to as p.Gln368Glu. It is studied for its potential role in predisposing individuals to elevated intraocular pressure and adult-onset primary open-angle glaucoma.
What each genotype means
Typical MYOC profile
This genotype represents the most common form of the MYOC gene in the general population. It is not associated with the specific p.Gln368Ter (also known as Q368X) variant linked to increased glaucoma risk.
Carried by the vast majority of individuals in all studied global populations.
Increased glaucoma risk
This genotype indicates the presence of one copy of the p.Gln368Ter (Q368X) variant. Research suggests this variant is associated with a higher risk of developing primary open-angle glaucoma and elevated intraocular pressure, though it does not guarantee the development of the condition. You should discuss regular eye health screenings and intraocular pressure monitoring with your ophthalmologist.
Found in approximately 0.1% to 0.3% of individuals in European populations, with lower frequencies observed in other ancestral groups.
Rare variant homozygous
This genotype indicates the presence of two copies of the p.Gln368Ter (Q368X) variant. While this variant is a known risk factor for primary open-angle glaucoma, clinical data on the homozygous state is extremely limited due to its rarity. Please consult with a medical professional or genetic counselor to discuss the implications for your ocular health.
Extremely rare in the general population, with very few documented cases in large-scale genomic databases.
Understanding the Variant
The variant rs74315330 is a missense mutation located within the MYOC gene, which sits on chromosome 1. In this specific change, the amino acid glutamine is replaced by glutamic acid at position 368 of the myocilin protein. This location is within the olfactomedin domain, a region of the protein critical for its proper folding and function. Because this change alters the protein's structure, researchers have long investigated whether it disrupts the normal drainage of fluid from the eye. While many genetic variants are benign, missense mutations in this region are of particular interest to ophthalmologists and geneticists because they may interfere with the trabecular meshwork, the tissue responsible for regulating intraocular pressure. Understanding this variant requires looking at how it might influence the physical properties of the myocilin protein within the eye's complex drainage system.
The Role of the MYOC Gene
The MYOC gene provides instructions for making a protein called myocilin. This protein is expressed in several parts of the eye, most notably in the trabecular meshwork, which is the spongy tissue that drains aqueous humor—the fluid that maintains eye pressure. When the MYOC gene functions correctly, it helps maintain the structural integrity of these tissues. However, when mutations occur, the resulting abnormal myocilin protein can accumulate within the cells of the trabecular meshwork. This accumulation is thought to cause cellular stress and dysfunction, potentially leading to an increase in intraocular pressure. Elevated pressure is a primary risk factor for glaucoma, a condition that can damage the optic nerve and lead to vision loss. Research into MYOC has been ongoing since the late 1990s, establishing it as one of the first genes linked to hereditary forms of glaucoma.
Research and Evidence Strength
The evidence linking rs74315330 to primary open-angle glaucoma (POAG) is considered limited but significant in specific contexts. While some studies have identified this variant in a small percentage of glaucoma patients, it is not a definitive cause of the disease for everyone who carries it. The penetrance—the likelihood that a person with the variant will actually develop the condition—is not absolute. Many individuals who carry this variant may never develop glaucoma, suggesting that other genetic, environmental, or lifestyle factors play a major role. Because glaucoma is a multifactorial disease, the presence of this variant is often viewed as a risk factor rather than a diagnostic indicator. Current research continues to explore how this variant interacts with other genetic markers and polygenic risk scores to influence the overall risk of developing vision-related complications in adulthood.
Population Frequency
The rs74315330 variant is relatively rare in the general population, appearing in approximately 0.1% to 0.2% of individuals of European descent. However, its frequency is notably higher among individuals already diagnosed with primary open-angle glaucoma, where it is found in roughly 3% to 4% of cases. This enrichment in the patient population is what drives scientific interest in the variant. It is important to note that population frequencies can vary significantly based on ancestry, and much of the existing data is heavily skewed toward European cohorts. Because of this, the clinical relevance of the variant may differ across diverse global populations. Researchers emphasize that while the variant is more common in glaucoma patients than in the general public, it remains a rare finding overall, and its absence does not rule out the possibility of developing glaucoma.
What This Information Means for You
If you have received information about your status for rs74315330, it is important to understand that this is not a medical diagnosis. Genetic testing for this variant does not predict with certainty whether you will develop glaucoma. Because the condition is complex and influenced by many factors, having this variant does not mean you are destined to lose your vision, nor does lacking it guarantee perfect eye health. This information should be used as a tool to facilitate a conversation with your eye care professional. Regular comprehensive eye exams, which include measuring intraocular pressure and evaluating the optic nerve, remain the gold standard for monitoring eye health. If you are concerned about your risk, discuss your family history and genetic findings with an ophthalmologist or a genetic counselor who can provide personalized guidance based on your specific clinical profile.
How common is this variant?
The rs74315330 variant is found in approximately 0.1-0.2% of general European populations and is present in about 3-4% of primary open-angle glaucoma cases.
Frequently asked questions
Does having the rs74315330 variant mean I will get glaucoma?
No, having this variant does not mean you will develop glaucoma. It is considered a risk factor, but many people with the variant never develop the disease, and many people with glaucoma do not have this variant.
Should I get tested for MYOC variants?
Genetic testing for glaucoma is generally not recommended for the general population. If you have a strong family history of glaucoma, you should discuss the potential benefits and limitations of genetic testing with an ophthalmologist or genetic counselor.
What is the difference between POAG and other types of glaucoma?
Primary open-angle glaucoma (POAG) is the most common form of the disease, characterized by a slow, painless increase in eye pressure. Other types, such as angle-closure glaucoma, have different underlying causes and physical characteristics in the eye.
How can I lower my risk of glaucoma?
The most effective way to manage glaucoma risk is through regular, comprehensive eye exams. Early detection allows for treatments that can help manage intraocular pressure and prevent damage to the optic nerve.
Sources & further reading
Educational information only, last refreshed 9/22/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs74315330?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in MYOC
Encodes the classical Gln368STOP mutation in myocilin, a well-validated genetic cause of juvenile- and adult-onset primary open-angle glaucoma.
A major missense variant in the myocilin olfactomedin domain causative of juvenile- and adult-onset primary open-angle glaucoma.
A pathogenic point mutation in MYOC strongly linked to autosomal dominant primary open-angle glaucoma with high intraocular pressure.
A pathogenic missense variant in myocilin causing trabecular meshwork disruption and juvenile-onset open-angle glaucoma.
Known as the Gln368STOP mutation in MYOC, this nonsense variant is a well-established cause of autosomal dominant juvenile- and adult-onset primary open-angle glaucoma.
A pathogenic missense variant (p.Gln368Ter) in the MYOC gene, a major genetic risk factor for primary open-angle glaucoma.