CRYAA rs104894335: Understanding Congenital Cataract Variants
The rs104894335 variant is a rare genetic change located within the CRYAA gene. It is associated with the development of autosomal dominant congenital and pediatric cataracts, which affect the clarity of the eye's lens.
What each genotype means
Typical CRYAA gene profile
This genotype represents the common, non-variant form of the CRYAA gene. It is associated with normal alpha-crystallin protein function in the lens of the eye.
This is the most common genotype found in the general population.
Potential cataract risk variant
This genotype indicates the presence of a rare variant in the CRYAA gene, which has been linked to autosomal dominant congenital cataracts in clinical literature. Because this variant is extremely rare, its presence should be discussed with a medical professional or genetic counselor to understand its clinical relevance for your specific health history.
This genotype is extremely rare, with an allele frequency reported as less than 0.00001 in large population databases like gnomAD.
Rare homozygous variant profile
This genotype indicates that both copies of the CRYAA gene carry this rare variant. While most research on this variant focuses on its dominant inheritance pattern, you should consult with a clinical geneticist to interpret the implications of this specific result for your eye health.
This genotype is exceptionally rare and is not typically observed in general population cohorts.
What is rs104894335?
The rs104894335 variant is a specific change in the DNA sequence of the CRYAA gene. In genetics, an rsID (reference SNP cluster ID) acts as a unique identifier for a specific location in the human genome where a variation may occur. This particular variant is classified as a missense mutation, meaning it results in a single amino acid change within the protein produced by the gene. Because this variant is extremely rare in the general population, it is primarily studied in the context of clinical genetics and ophthalmology. It is not a common variation found in the general public, but rather a specific alteration that has been identified in individuals presenting with certain types of vision-related conditions. Understanding such variants helps researchers map the genetic architecture of eye development and the underlying causes of inherited lens opacities.
The Role of the CRYAA Gene
The CRYAA gene provides instructions for making a protein called alpha-A crystallin. This protein is a member of the crystallin family, which are the primary structural proteins found in the lens of the eye. Alpha-A crystallin acts as a molecular chaperone, meaning it helps other proteins maintain their correct shape and prevents them from clumping together. In the lens, transparency is essential for clear vision, and this transparency depends on the precise organization of crystallin proteins. When the CRYAA gene is altered, the resulting alpha-A crystallin protein may not function correctly. This can lead to the aggregation of proteins within the lens cells, causing them to become cloudy or opaque. This process is the fundamental mechanism behind the formation of cataracts, which are areas of cloudiness that obstruct the passage of light to the retina.
Research and Clinical Associations
Scientific research has linked pathogenic variants in the CRYAA gene to autosomal dominant congenital and pediatric cataracts. Congenital cataracts are present at birth or develop shortly thereafter, while pediatric cataracts occur during childhood. The evidence for rs104894335 specifically suggests it is a pathogenic variant, meaning it is likely to cause or contribute to the development of these conditions. However, the strength of evidence for many rare variants can be limited, as they are often identified in small family studies rather than large-scale population cohorts. Research into these variants is crucial for clinical diagnostics, as it allows medical professionals to better understand the genetic basis of a patient's vision impairment. It is important to note that while genetic associations are strong, the clinical expression of these variants can vary between individuals, even within the same family.
Population Frequency
The rs104894335 variant is exceptionally rare in the general population. According to data from the Genome Aggregation Database (gnomAD), the allele frequency for this variant is less than 0.00001. This extremely low frequency indicates that the variant is not a common polymorphism found in the general public, but is instead a rare mutation associated with specific clinical phenotypes. Because it is so uncommon, it is rarely encountered in standard population-wide genetic screening. Its presence is typically investigated only when a patient presents with clinical symptoms of congenital or pediatric cataracts and a genetic cause is suspected by a specialist.
What This Information Means for You
If you or a family member have been identified as carrying this variant, it is important to understand that this information is for educational purposes and does not constitute a medical diagnosis. Genetic variants in the CRYAA gene are complex, and their impact can be influenced by other genetic and environmental factors. If you have concerns about your vision or a family history of cataracts, the most appropriate step is to consult with a medical professional, such as an ophthalmologist or a genetic counselor. They can provide a clinical evaluation, discuss the implications of genetic findings, and offer guidance on management or monitoring. Never make medical decisions based solely on genetic data without professional clinical oversight. Genetic testing results should always be interpreted within the context of a comprehensive physical examination and personal medical history.
How common is this variant?
The rs104894335 variant is extremely rare, with a gnomAD allele frequency of less than 0.00001 across global populations.
Frequently asked questions
What is a congenital cataract?
A congenital cataract is a clouding of the lens of the eye that is present at birth. It can affect one or both eyes and may range from small, insignificant opacities to dense clouds that significantly impair vision.
Is rs104894335 always associated with cataracts?
While rs104894335 is classified as a pathogenic variant linked to cataracts, the clinical expression can vary. Not every individual with a specific genetic variant will experience the same severity of symptoms.
Can I prevent cataracts caused by this variant?
Currently, there are no known ways to prevent the development of cataracts caused by specific genetic mutations like those in CRYAA. Management typically involves monitoring by an eye specialist and surgical intervention if vision is significantly affected.
Should I get tested for this variant?
Genetic testing for specific variants is usually recommended by a doctor if there is a clinical reason, such as a personal or family history of early-onset cataracts. You should discuss the necessity and implications of such testing with a genetic counselor.
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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Promoter variant in CRYAA associated with age-related cataracts.
A missense mutation altering the structural chaperone function of lens alpha-crystallin, causing dominant zonular cataracts.
A pathogenic missense mutation in the alpha-A crystallin gene causing autosomal dominant congenital cataracts.
This variant in the alpha A-crystallin gene has been studied for its potential association with susceptibility to nuclear age-related cataracts in Han Chinese populations.