CYP1B1 rs74315356: Understanding This Genetic Variant
The rs74315356 variant is a specific genetic change located within the CYP1B1 gene. It is recognized in clinical databases as a pathogenic variant associated with primary congenital glaucoma, a rare and serious eye condition.
What each genotype means
Typical CYP1B1 function
This genotype represents the most common sequence found in the general population for this specific location in the CYP1B1 gene. It is not associated with the increased risk of primary congenital glaucoma linked to this variant.
This is the most common genotype, found in the vast majority of individuals across all global populations.
Carrier of rare variant
You carry one copy of the variant associated with primary congenital glaucoma. Because this condition typically follows an autosomal recessive inheritance pattern, carrying a single copy is generally not sufficient to cause the disease, though you should consult with a genetic counselor to understand your specific family risk.
This genotype is very rare, occurring in approximately 1 in 10,000 individuals based on current population databases.
Increased risk profile
You carry two copies of this variant, which is documented in clinical literature as a loss-of-function change associated with primary congenital glaucoma. Please discuss these findings with an ophthalmologist or a clinical geneticist to understand the clinical implications for your eye health.
This genotype is extremely rare in the general population.
What is the rs74315356 Variant?
The rs74315356 variant is a single nucleotide polymorphism (SNP) found within the CYP1B1 gene. In genetic terms, this variant represents a specific alteration in the DNA sequence where one nucleotide is substituted for another. This change can lead to the production of an altered protein or a reduction in the protein's normal function. Because the CYP1B1 gene provides instructions for making an enzyme that plays a critical role in eye development, changes in this gene can have significant biological consequences. This specific variant is classified in clinical databases as a missense mutation, meaning the change in the DNA code results in a different amino acid being incorporated into the final protein structure, which may disrupt its ability to function correctly within the body's cells.
The Role of the CYP1B1 Gene
The CYP1B1 gene encodes the cytochrome P450 1B1 enzyme. This enzyme is part of a large family of proteins involved in the metabolism of various substances, including hormones and fatty acids. In the context of the eye, CYP1B1 is essential for the normal development of the trabecular meshwork, the tissue responsible for draining fluid from the eye. When this gene is mutated, the resulting enzyme may be inactive or absent, leading to impaired drainage of aqueous humor. This buildup of fluid increases intraocular pressure, which is the hallmark of primary congenital glaucoma. Research has consistently identified CYP1B1 as a primary causative gene for this condition, particularly in cases that follow an autosomal recessive inheritance pattern, where an individual must inherit two copies of a pathogenic variant to manifest the disease.
Research and Clinical Associations
Scientific research has established a strong link between pathogenic variants in CYP1B1 and primary congenital glaucoma. The rs74315356 variant is documented in clinical resources like ClinVar as a pathogenic mutation. Studies focusing on familial cases of glaucoma often utilize genetic sequencing to identify these variants, especially in populations where consanguineous marriages are more common, as this increases the likelihood of inheriting two copies of a recessive mutation. While the association with primary congenital glaucoma is well-supported, the clinical expression can be variable. It is important to note that the presence of a pathogenic variant does not guarantee a specific clinical outcome, as other genetic and environmental factors also contribute to eye health. Genetic testing for such variants is typically performed in a clinical setting to assist in diagnosis and family counseling.
Population Frequency and Distribution
The rs74315356 variant is considered rare in the general population. According to large-scale genomic databases like gnomAD, the allele frequency is extremely low, approximately 0.00005. This rarity is consistent with its classification as a pathogenic variant for a severe, rare disease. Because it is a recessive condition, the variant is most frequently identified in studies of families with a history of congenital glaucoma. Its prevalence can appear higher in specific geographic regions or ethnic groups where there is a higher rate of consanguinity, which allows rare recessive alleles to be passed down and expressed more frequently. Outside of these specific contexts, the variant is seldom encountered in the general population, highlighting the importance of targeted genetic screening for individuals with a family history of early-onset glaucoma.
What This Information Means for You
If you or a family member have been identified as a carrier of a CYP1B1 variant, it is essential to understand that this information is for educational purposes and does not constitute a medical diagnosis. Genetic variants are only one piece of a complex puzzle regarding health. If you have concerns about glaucoma or your family's eye health, the most appropriate step is to consult with an ophthalmologist or a genetic counselor. These professionals can provide context based on your specific clinical history, perform necessary eye examinations, and discuss whether genetic testing is appropriate for you or your family members. Never make medical decisions based solely on genetic data without professional guidance. A clinician can help interpret these results in the context of your overall health and provide personalized recommendations for monitoring and care.
How common is this variant?
The rs74315356 variant is very rare, with a reported allele frequency of approximately 0.00005 in the gnomAD database.
Frequently asked questions
What is primary congenital glaucoma?
Primary congenital glaucoma is a rare, inherited eye condition present at birth or developing in early childhood. It is caused by abnormal development of the eye's drainage system, leading to high pressure that can damage the optic nerve.
Is rs74315356 the only cause of glaucoma?
No, glaucoma is a complex group of diseases with many different causes. While CYP1B1 variants are a known cause of congenital forms, most cases of adult-onset glaucoma are influenced by a combination of many different genes and environmental factors.
Should I get tested for this variant?
Genetic testing is usually recommended only if there is a family history of congenital glaucoma or if a doctor suspects a genetic cause based on clinical symptoms. You should discuss the necessity and implications of testing with a genetic counselor or your eye doctor.
What does it mean to be a carrier?
Being a carrier means you have one copy of a recessive variant but do not show symptoms of the condition. Carriers can pass the variant to their children, who may then be at risk if they inherit a second copy from the other parent.
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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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.
A well-characterized loss-of-function missense variant causing primary congenital glaucoma through abnormal trabecular meshwork development.
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.