HEXA rs28941770: Understanding This Tay-Sachs Carrier Variant
The rs28941770 variant is a specific genetic change in the HEXA gene known as a splice-donor mutation. It is recognized in clinical genetics as a pathogenic allele associated with carrier status for Tay-Sachs disease.
What each genotype means
Typical HEXA gene profile
This genotype represents the common, functional sequence for the HEXA gene at this location. Individuals with this profile do not carry this specific Tay-Sachs disease-associated variant.
This is the most common genotype found in the general population across all ancestries.
Tay-Sachs carrier status
This genotype indicates you carry one copy of the c.1421+1G>C variant, which is a known pathogenic mutation associated with Tay-Sachs disease. As this condition is inherited in an autosomal recessive manner, carriers typically do not exhibit symptoms but should consult with a genetic counselor regarding reproductive risks.
This genotype is most frequently observed in individuals of Ashkenazi Jewish ancestry, with an estimated carrier frequency of approximately 1 in 250 to 1 in 30 depending on the specific sub-population.
Potential HEXA deficiency
This genotype indicates the presence of two copies of the c.1421+1G>C variant, which is associated with the clinical spectrum of HEXA disorders, including Tay-Sachs disease. If you have this result, it is important to discuss these findings with a medical professional or clinical geneticist to understand the clinical implications for your health.
This genotype is extremely rare in the general population.
What is the rs28941770 Variant?
The variant rs28941770, technically described as c.1421+1G>C, is a specific alteration located within the HEXA gene. In genetics, a splice-donor variant like this occurs at the boundary of an exon and an intron, which are the coding and non-coding segments of a gene, respectively. This specific location is critical because it acts as a signal for the cellular machinery to correctly 'splice' or assemble the messenger RNA that provides instructions for building proteins. When this signal is disrupted by a mutation, the cell may fail to produce a functional protein, or it may produce a truncated, non-functional version. Because this variant directly interferes with the production of the HEXA enzyme, it is classified as a pathogenic variant in the context of recessive genetic conditions.
The Role of the HEXA Gene
The HEXA gene provides the instructions for creating the alpha subunit of an enzyme called beta-hexosaminidase A. This enzyme is essential for the normal function of lysosomes, which are the recycling centers of our cells. Specifically, beta-hexosaminidase A is responsible for breaking down a fatty substance known as GM2 ganglioside. When the HEXA gene contains mutations that prevent the production of this enzyme, GM2 ganglioside can accumulate to toxic levels within nerve cells in the brain and spinal cord. This accumulation is the underlying cause of GM2-gangliosidosis, the most well-known form of which is Tay-Sachs disease. Because the body requires functional enzymes to maintain cellular health, the absence of this protein leads to progressive neurodegeneration.
Research and Clinical Significance
Research into rs28941770 has established its role as a pathogenic variant linked to Tay-Sachs disease. Tay-Sachs is an autosomal recessive condition, meaning an individual must inherit two copies of a pathogenic variant—one from each parent—to manifest the disease. Individuals who carry only one copy of this variant are typically asymptomatic carriers. Clinical literature, including data from GeneReviews, identifies this variant as one of the known mutations screened for in populations where Tay-Sachs is more prevalent, such as the Ashkenazi Jewish community. While the evidence for its pathogenicity is strong, it is important to note that genetic testing for carrier status is complex. Clinical laboratories use this information to provide reproductive counseling, but it should never be used for self-diagnosis or to make independent medical decisions.
Population Frequency
The frequency of specific HEXA variants varies significantly across different ancestral groups. In the Ashkenazi Jewish population, carrier screening programs have been highly effective at identifying individuals with pathogenic HEXA variants. According to gnomAD data, the allele frequency for this specific variant is approximately 0.004 in the Ashkenazi Jewish population. This means that while it is a known founder variant in this group, it is still relatively rare. Because Tay-Sachs is a recessive condition, the risk of having an affected child is primarily a concern when both parents are carriers of pathogenic variants in the HEXA gene. Genetic counseling is the standard of care for individuals who receive a positive carrier result to understand their specific reproductive risks.
Navigating Genetic Information
If you have received information about your status regarding rs28941770, it is essential to place this in the correct clinical context. A carrier result does not mean you have or will develop Tay-Sachs disease. However, it does provide important information for family planning. You cannot 'treat' or 'change' your carrier status, as it is a permanent feature of your genetic code. The most appropriate step after receiving such information is to consult with a board-certified genetic counselor or a medical geneticist. These professionals can help interpret the results in the context of your family history and provide guidance on testing options for partners or other family members. Always rely on clinical-grade testing and professional medical advice rather than interpreting raw genetic data on your own.
How common is this variant?
The rs28941770 variant is a known founder allele in the Ashkenazi Jewish population with an approximate frequency of 0.004 in that group.
Frequently asked questions
What does it mean to be a Tay-Sachs carrier?
Being a carrier means you have one copy of a pathogenic HEXA variant and one functional copy. Carriers are generally healthy and do not experience symptoms of Tay-Sachs disease.
Is rs28941770 the only cause of Tay-Sachs?
No, there are many different mutations in the HEXA gene that can cause Tay-Sachs disease. This variant is just one of several that are monitored in clinical screening programs.
Should I be worried if I have this variant?
A carrier result is not a diagnosis of disease. However, it is important for family planning, and you should discuss the implications with a genetic counselor.
Can I get tested for this variant?
Yes, clinical genetic testing for HEXA variants is available through healthcare providers. It is recommended to use a certified laboratory for accurate results.
Sources & further reading
Educational information only, last refreshed 10/15/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Canonical splice junction variant (c.1073+1G>A) causing Tay-Sachs disease.
Pathogenic splice-junction variant (c.1073+1G>A / IVS9+1G>A) causing Tay-Sachs disease when in compound heterozygosity or homozygosity.
Pathogenic splice donor variant (c.1421+1G>C) in HEXA underlying carrier status for autosomal recessive infantile Tay-Sachs disease.
This HEXA variant is associated with Tay-Sachs disease, particularly late-onset forms.
Pathogenic splice junction mutation (c.1421+1G>C) in HEXA leading to Tay-Sachs disease.
Pathogenic HEXA splice donor site mutation (c.1073+1G>A) causing Tay-Sachs disease, common in carrier screening panels for Ashkenazi Jewish and French Canadian ancestry.