CYP1B1 rs121913530: Understanding Primary Congenital Glaucoma
The rs121913530 variant is a specific genetic alteration located within the CYP1B1 gene. It is recognized in clinical literature as a loss-of-function variant associated with the development of primary congenital glaucoma, a condition affecting the eye's drainage structures.
What each genotype means
Typical CYP1B1 function
This genotype represents the most common genetic sequence for this location in the CYP1B1 gene. It is not associated with the loss-of-function effects linked to primary congenital glaucoma in scientific literature.
This is the most common genotype observed globally across all major ancestral populations.
Carrier of variant allele
You carry one copy of the variant allele associated with reduced or absent CYP1B1 enzyme activity. While this variant is linked to primary congenital glaucoma when two copies are present, carrying a single copy typically does not cause the condition, though it may act as a modifier in complex ocular development.
This genotype is rare in most global populations, with a higher frequency observed in specific Middle Eastern populations.
Reduced enzyme activity
This genotype indicates the presence of two copies of the variant allele, which is associated with a loss of function in the CYP1B1 enzyme. Research links this specific genetic profile to an increased risk of primary congenital glaucoma, a condition involving abnormal development of the eye's drainage structures. Please discuss these findings with an ophthalmologist or genetic counselor to understand your specific clinical context.
This genotype is very rare globally, occurring most frequently in populations with high rates of consanguinity where autosomal recessive conditions are more commonly observed.
What is rs121913530?
The rs121913530 variant is a specific change in the DNA sequence of the CYP1B1 gene. In genetics, an rsID (reference SNP cluster ID) acts as a unique identifier for a specific location in the human genome. This particular variant is classified as a missense mutation, meaning it results in a change to the amino acid sequence of the protein that the gene encodes. Because this change occurs in a critical region of the gene, it can disrupt the normal production or function of the resulting enzyme. Researchers study this variant to understand how small changes in our genetic code can lead to significant differences in biological function, particularly in the context of ocular development.
The Role of the CYP1B1 Gene
The CYP1B1 gene provides instructions for making an enzyme called cytochrome P450 1B1. This enzyme is part of a large family of proteins involved in the metabolism of various substances within the body. In the context of the eye, CYP1B1 is expressed in tissues that are essential for proper development and function, including the trabecular meshwork. The trabecular meshwork acts as a drainage system for the eye, regulating the outflow of aqueous humor to maintain healthy intraocular pressure. When the CYP1B1 enzyme is absent or non-functional, the development of these drainage structures can be impaired, which is a hallmark of primary congenital glaucoma.
Research and Clinical Associations
Scientific research has established a strong link between loss-of-function mutations in CYP1B1 and primary congenital glaucoma (PCG). PCG is an autosomal recessive condition, meaning that an individual typically needs to inherit two copies of a pathogenic variant—one from each parent—to manifest the condition. While rs121913530 is well-characterized as a pathogenic variant in this context, it is important to note that the clinical expression of PCG can be variable. Some individuals with identical genotypes may show different levels of disease severity. Current evidence suggests that while CYP1B1 mutations are a primary cause of PCG, other genetic and environmental factors may also influence the development and progression of the disease.
Population Frequency
The frequency of the rs121913530 variant varies significantly across different global populations. According to data from the Genome Aggregation Database (gnomAD), the minor allele frequency is approximately 0.001 globally. However, this variant is observed at higher frequencies in specific populations, particularly in regions where consanguineous marriages are more common. This geographic clustering is a known phenomenon in the study of autosomal recessive disorders, as the likelihood of inheriting two copies of a rare variant increases within families or communities with shared ancestry. Understanding these population-specific frequencies is crucial for genetic counseling and for researchers investigating the prevalence of hereditary eye conditions in different parts of the world.
Navigating Genetic Information
If you or a family member have questions about this variant or concerns regarding eye health, it is essential to consult with a qualified healthcare professional, such as an ophthalmologist or a genetic counselor. Genetic information can be complex, and a clinical expert can provide context based on your personal and family medical history. It is important to remember that the presence of a genetic variant does not always guarantee the development of a condition, and clinical diagnosis requires a comprehensive eye examination. Never use genetic data to make independent medical decisions or to diagnose yourself. Always discuss any findings from genetic testing with a clinician who can interpret the results within the appropriate medical framework.
How common is this variant?
The rs121913530 variant has a global minor allele frequency of approximately 0.001, with higher observed frequencies in Middle Eastern populations.
Frequently asked questions
What is primary congenital glaucoma?
Primary congenital glaucoma is a rare, hereditary condition present at birth or in early infancy. It is caused by the abnormal development of the eye's drainage system, leading to increased intraocular pressure that can damage the optic nerve.
Does having this variant mean I will develop glaucoma?
Not necessarily. Because this condition is autosomal recessive, inheriting one copy of the variant usually does not cause the disease. A clinical diagnosis requires a professional eye examination.
Can I be tested for this variant?
Genetic testing for specific variants is available through clinical laboratories, usually ordered by a physician or genetic counselor. You should discuss the necessity and implications of such testing with your healthcare provider.
Is there a cure for CYP1B1-related glaucoma?
While there is no cure for the underlying genetic cause, primary congenital glaucoma is managed through surgical interventions and medical treatments to control eye pressure. Early detection and management are critical for preserving vision.
Sources & further reading
Educational information only, last refreshed 10/14/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs121913530?
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 CYP1B1
This variant (p.Asn453Ser, formerly Val432Leu) in the CYP1B1 gene is associated with altered enzyme activity and has been investigated for susceptibility to various cancers, including breast and prostate cancer.
This variant (p.Gly61Glu) is a well-documented pathogenic mutation associated with primary congenital glaucoma (PCG) and is also studied for its role in oxidative stress and drug response pathways.
A missense variant in CYP1B1 (p.Ala119Ser) associated with primary congenital glaucoma and juvenile open-angle glaucoma risk.
Missense variant in CYP1B1 associated with primary congenital glaucoma.
A classic founder missense mutation in CYP1B1 responsible for early-onset recessive infantile and juvenile glaucoma.
Associated with estrogen metabolism and steroid hormone metabolite ratios.