TP53 rs78378222: Understanding This Polyadenylation Variant
The rs78378222 variant is a rare genetic change located in the 3' untranslated region (UTR) of the TP53 gene. It is associated with altered gene expression and has been studied for its potential links to susceptibility for certain types of cancer.
What each genotype means
Typical TP53 polyadenylation profile
This is the most common genotype, representing the standard sequence at this position in the TP53 gene. Research indicates that individuals with this genotype do not carry the specific polyadenylation signal alteration associated with increased cancer risk in some studies. This result does not rule out other genetic or environmental factors that may influence cancer risk.
This is the major allele genotype, carried by the vast majority of individuals across all global populations.
Altered TP53 polyadenylation signal
You carry one copy of the C allele, which is located in the polyadenylation signal of the TP53 gene. Some research suggests this variant may influence TP53 expression and has been statistically associated with an increased risk for certain cancers, such as glioma and non-melanomatous skin cancer, in specific populations. Because the evidence is limited and the clinical significance is still being studied, you should discuss any concerns about cancer screening or family history with a qualified healthcare provider or genetic counselor.
The C allele is rare, with a minor allele frequency of approximately 0.015 in European populations and less than 0.001 in East Asian and African populations.
Altered TP53 polyadenylation signal
You carry two copies of the C allele, which is located in the polyadenylation signal of the TP53 gene. This variant has been linked in some studies to altered TP53 transcription termination and a potential increase in susceptibility to certain malignancies, including brain and skin cancers. As this is a rare genotype and the clinical impact remains a subject of ongoing research, please consult with a medical professional to interpret these findings in the context of your personal and family health history.
This homozygous genotype is extremely rare, occurring at a very low frequency globally, consistent with the low prevalence of the C allele.
What is rs78378222?
The rs78378222 variant is a single nucleotide polymorphism (SNP) located on chromosome 17 within the TP53 gene. Specifically, it sits in the 3' untranslated region (3' UTR), a segment of the gene that does not code for protein but plays a critical role in regulating how much protein is produced. This specific variant involves a change from an adenine (A) to a cytosine (C) nucleotide. This change occurs within the polyadenylation signal, which is the molecular 'stop sign' that tells the cell where to end the transcription of the TP53 messenger RNA (mRNA). By altering this signal, the variant can interfere with the normal processing of the mRNA, potentially leading to changes in the stability or expression levels of the p53 protein.
The Role of the TP53 Gene
The TP53 gene is one of the most important genes in human biology, often referred to as the 'guardian of the genome.' It provides instructions for making the p53 protein, which acts as a tumor suppressor. This protein monitors the health of a cell's DNA; if it detects damage, it can pause the cell cycle to allow for repairs or trigger programmed cell death (apoptosis) if the damage is too severe to fix. By preventing cells with mutated or damaged DNA from dividing, p53 helps prevent the development of tumors. Because of its vital role in maintaining genomic stability, any variation that significantly reduces the function or expression of p53 can theoretically impact the body's ability to suppress abnormal cell growth.
Research and Associations
Scientific research has investigated the association between the rs78378222 variant and various health outcomes. Studies have linked the 'C' allele to an increased risk for certain cancers, including glioma, prostate cancer, and colorectal adenoma. The mechanism is thought to involve impaired 3'-end processing of TP53 mRNA, which may reduce the efficiency of p53 production. However, the evidence is considered limited and complex. For instance, while some studies show a higher risk for specific tumors, others have found no significant association with common cancers like breast cancer. Interestingly, some research has even suggested that carriers of the variant might experience different outcomes in tumor progression, such as improved survival in certain glioma cases. Because these findings are based on statistical associations across different populations, they do not imply a direct cause-and-effect relationship for any individual.
Population Frequency
The rs78378222 variant is considered rare in the general population. Data from large-scale genomic databases indicate that the minor allele frequency (the 'C' allele) is approximately 0.015 in European populations, while it is significantly lower, often less than 0.001, in East Asian and African populations. Because the variant is uncommon, most individuals carry the standard 'A' allele on both chromosomes. The rarity of this variant means that it is not a common driver of cancer in the general public, and its presence is typically identified only through specialized genetic testing or research studies.
What This Information Means for You
If you have learned that you carry the rs78378222 variant, it is important to understand that this is a statistical association, not a medical diagnosis. Genetic variants are only one of many factors—including environment, lifestyle, and other genetic influences—that contribute to health outcomes. This information should not be used to predict personal health or to make medical decisions. If you are concerned about your family history of cancer or your personal health risks, the most appropriate step is to consult with a qualified healthcare provider or a genetic counselor. They can help you interpret your results in the context of your overall health and provide guidance on appropriate screening or preventative measures based on established clinical guidelines.
How common is this variant?
The rs78378222 variant is rare, with a minor allele frequency of approximately 0.015 in Europeans and less than 0.001 in East Asian and African populations.
Frequently asked questions
Is rs78378222 a cause of cancer?
No, rs78378222 is a genetic variant associated with a statistical increase in risk for certain cancers, but it is not a direct cause. Cancer is a complex disease influenced by many genetic, environmental, and lifestyle factors.
Should I get tested for this variant?
Routine testing for this variant is not standard clinical practice. If you have a strong family history of cancer, you should speak with a genetic counselor to discuss whether clinical genetic testing is appropriate for your situation.
What does it mean if I have the 'C' allele?
Having the 'C' allele means you carry a variant that may slightly alter how the TP53 gene is processed. This is a common finding in genetic research, but it does not mean you will develop cancer.
Can I change my risk if I have this variant?
While you cannot change your genetics, you can focus on healthy lifestyle choices such as regular screenings, avoiding tobacco, and maintaining a balanced diet. Always discuss your specific health risks with a healthcare professional.
Sources & further reading
Educational information only, last refreshed 9/26/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Pathogenic missense variant (p.Arg248Gln) associated with Li-Fraumeni syndrome.
Functional codon 72 polymorphism (Arg72Pro) affecting apoptotic capability and associated with differential susceptibility to multiple cancer types.
Pathogenic hotspot variant (p.Arg273His) in TP53 predisposing carriers to early-onset sarcomas, breast cancers, and leukemias.
Li-Fraumeni syndrome missense variant (p.Arg248Trp) causing loss of tumor suppressor function and multi-cancer predisposition.
Synonymous and regulatory variant in linkage with TP53 codon 72 that modulates blastocyst implantation competence and the risk of recurrent implantation failure.
3' UTR hypomorphic variant in TP53 that impairs proper polyadenylation and significantly confers elevated risk for basal cell carcinoma, glioma, and other cancers.