CTDP1 rs2279103: Understanding This Genetic Variant
The rs2279103 variant is a single nucleotide polymorphism located within the CTDP1 gene. It has been identified in research as a candidate marker potentially associated with individual responses to the chemotherapy medication gemcitabine.
What each genotype means
Typical gemcitabine response profile
This genotype represents the major allele combination for this variant. Research into this specific SNP in the CTDP1 gene has suggested potential associations with gemcitabine treatment outcomes, though the evidence remains limited and requires further validation. Please discuss your treatment plan and any concerns regarding medication response with your clinician or pharmacist.
This is the most common genotype globally, though frequencies vary significantly by ancestry.
Potential gemcitabine response variation
Carrying one copy of the minor allele may be associated with differences in how the body processes or responds to gemcitabine, based on preliminary pathway-based studies. Because the evidence for this variant is currently limited, this result should not be used to make clinical decisions. Always consult with your healthcare provider or pharmacist regarding your specific medication therapy.
This genotype is observed at varying frequencies, with higher prevalence noted in East Asian populations compared to other groups.
Potential gemcitabine response variation
Carrying two copies of the minor allele may be associated with differences in gemcitabine outcomes, as identified in candidate functional SNP studies. The clinical significance of this finding is currently limited and not fully established in medical practice. Please consult your clinician or pharmacist to discuss how this information relates to your personal health and medication management.
This genotype is less common than the major allele combinations, with higher observed frequencies in individuals of East Asian ancestry.
What is rs2279103?
The rs2279103 variant is a specific change in the DNA sequence, known as a single nucleotide polymorphism (SNP), located within the CTDP1 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This particular variant is cataloged in international databases that track human genetic diversity. While many SNPs have no observable effect on health or traits, researchers study specific variants like rs2279103 to determine if they correlate with differences in how people process medications or their susceptibility to certain conditions. Because this variant is located within a gene that plays a role in cellular regulation, it has been the subject of pathway-based analyses aimed at understanding its potential functional impact on biological processes.
The Role of the CTDP1 Gene
The CTDP1 gene provides the instructions for producing a protein known as carboxy-terminal domain phosphatase 1. This protein is essential for regulating the activity of RNA polymerase II, an enzyme responsible for initiating transcription—the process by which genetic information is copied into RNA to eventually build proteins. By controlling this enzyme, the CTDP1 protein helps ensure that gene expression is properly managed within the cell. While severe mutations in this gene are known to cause rare, inherited conditions such as congenital cataracts, facial dysmorphism, and neuropathy (CCFDN), common variants like rs2279103 are generally studied for their more subtle influences on biological pathways, such as those involved in drug metabolism or cellular response to external stressors.
Research and Evidence Strength
The evidence linking rs2279103 to clinical outcomes is currently considered limited. Research into this variant has primarily focused on its potential role in influencing how patients respond to gemcitabine, a chemotherapy drug used to treat various types of cancer. These studies often utilize pathway-based analyses to hypothesize how genetic variations might alter the efficacy or toxicity of a treatment. However, it is important to note that a statistical association in a research study does not necessarily mean the variant is the direct cause of a clinical outcome. Because the evidence is preliminary, it is not currently used as a standard diagnostic tool or a definitive predictor of drug response. Further large-scale clinical validation is required to understand the true significance of this variant in a medical context.
Population Frequency
Genetic variants are distributed differently across global populations, and rs2279103 is no exception. Current data indicates that the frequency of this variant is higher in Chinese populations compared to other ancestral groups. Understanding these frequency differences is a critical part of genomic research, as it helps scientists account for population-specific genetic architecture when studying traits or drug responses. When a variant is more common in a specific group, researchers must be careful to ensure that findings are not misinterpreted or generalized inappropriately to other populations. This variation in frequency highlights the importance of diverse genomic studies to ensure that medical insights are applicable and accurate across all human ancestries.
What You Can Do With This Information
If you have received information about your rs2279103 genotype, it is important to view it as a piece of research-level data rather than a medical diagnosis. Because the evidence linking this variant to gemcitabine outcomes is limited, it should not be used to make decisions about your healthcare or treatment plans. Genetic associations are complex and often involve many different genes and environmental factors working together. If you are undergoing treatment with gemcitabine or any other medication, you should always discuss your concerns, medical history, and any genetic testing results with your clinician or pharmacist. They are the best resource for interpreting how your unique genetic profile might relate to your specific clinical situation and for ensuring your treatment is safe and effective.
How common is this variant?
The rs2279103 variant shows notable variation in frequency across global populations, with research indicating a higher prevalence in Chinese populations.
Frequently asked questions
Is rs2279103 a diagnostic test for cancer?
No, rs2279103 is not a diagnostic test for cancer. It is a genetic variant that has been studied for its potential association with drug response, not as a marker for the presence or absence of disease.
Should I change my chemotherapy based on this SNP?
You should never change your medication or treatment plan based on a single genetic variant. Always consult with your oncologist or pharmacist before making any changes to your prescribed therapy.
What does 'limited evidence' mean in genetics?
Limited evidence means that while some studies have suggested a potential link, the findings have not been consistently replicated or confirmed in large-scale clinical trials. It suggests that more research is needed before the information can be used for clinical decision-making.
Where can I find more information about my specific genotype?
You can discuss your genetic results with a certified genetic counselor or your primary healthcare provider. They can help you understand the context of your results and what they mean for your health.
Sources & further reading
Educational information only, last refreshed 9/25/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs2279103?
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 — $29