MYOC rs74315357: What Your Genotype Means
The rs74315357 variant is a rare genetic change located within the MYOC gene. It is associated with an increased risk of developing juvenile-onset open-angle glaucoma, a condition characterized by elevated pressure within the eye.
What each genotype means
Typical MYOC genotype
This is the most common genotype found in the general population. It does not contain the specific rare variant associated with juvenile-onset open-angle glaucoma.
This genotype is found in the vast majority of the global population.
Rare variant carrier
This genotype includes one copy of the rare variant associated with trabecular meshwork disruption and juvenile-onset open-angle glaucoma. Because this condition is typically inherited in an autosomal dominant manner, carrying this variant may increase the risk of developing glaucoma, though clinical expression can be variable.
This genotype is extremely rare, with an allele frequency reported at less than 0.00001 in large population databases like gnomAD.
Rare homozygous variant
This genotype indicates the presence of the rare variant on both copies of the MYOC gene. While the variant is linked to juvenile-onset open-angle glaucoma, the specific clinical implications of being homozygous are not well-documented in current literature due to the extreme rarity of this genotype.
This genotype is exceptionally rare and is not typically observed in standard population cohorts.
Understanding the rs74315357 Variant
The rs74315357 variant is a specific change in the DNA sequence of the MYOC gene, which is located on chromosome 1. In genetics, a single nucleotide polymorphism (SNP) like this represents a variation at a single position in the genome. While many variants are common and have no impact on health, rs74315357 is categorized as a pathogenic missense variant. This means the change in the DNA code leads to the production of an altered protein. Because this variant is extremely rare in the general population, it is primarily studied in the context of specific families or individuals who have been diagnosed with early-onset eye conditions. Researchers track these variants to understand how small changes in our genetic blueprint can influence the structure and function of proteins essential for maintaining normal physiological processes in the eye.
The Role of the MYOC Gene
The MYOC gene provides instructions for making a protein called myocilin. This protein is expressed in various tissues of the eye, most notably in the trabecular meshwork. The trabecular meshwork acts as a drainage system for the eye, regulating the flow of fluid to maintain healthy intraocular pressure. When the MYOC gene functions normally, myocilin helps maintain the structural integrity and proper function of these drainage tissues. However, when pathogenic variants occur, the resulting myocilin protein may be misfolded. Research suggests that these misfolded proteins can accumulate within cells, potentially triggering a toxic gain-of-function effect. This accumulation can disrupt the normal drainage of fluid, leading to increased pressure inside the eye, which is a hallmark of glaucoma. Understanding this mechanism is a major focus of ongoing research into protein-misfolding diseases.
Research and Clinical Associations
Scientific literature identifies MYOC variants as a significant genetic factor in hereditary juvenile-onset open-angle glaucoma (JOAG). While the evidence for specific variants like rs74315357 is often limited to clinical case studies or small family cohorts, the broader association between MYOC mutations and glaucoma is well-documented. Studies indicate that these variants often follow an autosomal dominant inheritance pattern, meaning an individual only needs to inherit the variant from one parent to be at risk. It is important to note that while these variants are linked to glaucoma, they do not guarantee that an individual will develop the disease. Other genetic and environmental factors likely play a role in the onset and severity of the condition. Because the evidence for this specific variant is limited, clinicians often interpret such findings within the context of a patient's full clinical history and family background.
What This Information Means for You
If you have received information about this variant, it is essential to understand that genetic data is only one piece of a complex health puzzle. A variant in the MYOC gene does not constitute a medical diagnosis. If you are concerned about your eye health or have a family history of glaucoma, the most appropriate step is to consult with an ophthalmologist or a genetic counselor. These professionals can provide a comprehensive eye examination and interpret genetic findings in the context of your personal health. You cannot use this information to self-diagnose or predict future health outcomes with certainty. Avoid making medical decisions based solely on genetic reports. Instead, use this information as a starting point for a productive conversation with your healthcare provider, who can guide you through appropriate screening and monitoring strategies tailored to your specific needs.
How common is this variant?
The rs74315357 variant is extremely rare, with a reported allele frequency of less than 0.00001 in the gnomAD database.
Frequently asked questions
Does having this variant mean I will get glaucoma?
No, having a variant in the MYOC gene does not guarantee that you will develop glaucoma. While these variants are associated with an increased risk, many other factors influence whether the disease develops.
What is juvenile-onset open-angle glaucoma?
This is a form of glaucoma that typically presents before the age of 40. It involves increased pressure in the eye that can damage the optic nerve if left untreated.
Should I get tested for this variant?
Genetic testing for specific variants is usually recommended by a doctor if there is a strong family history of early-onset glaucoma. You should discuss the necessity and implications of such testing with a genetic counselor.
Is there a cure for MYOC-related glaucoma?
While there is no cure for the genetic cause itself, glaucoma is managed through treatments that lower eye pressure, such as eye drops, laser therapy, or surgery. Early detection is key to preserving vision.
Sources & further reading
Educational information only, last refreshed 9/22/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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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.
Missense mutation in MYOC (p.Gln368Glu) predisposing carriers to elevated intraocular pressure 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.
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.