What you carry at this position in your DNA and what research says about it.
Cancer Risk Trade-offs: 10/10 evidence, 22 publications.
You're viewing every possible genotype for this variant.
None of these is your result. Use the genotype toggle to compare them, then sign up and upload your DNA to see which one is yours.
Sample genotype (not yours): G/G
Higher Prostate and Liver Cancer Risk
Carrying two copies of the major G allele is associated with an increased risk of developing prostate, liver, and bladder cancers. Conversely, this genetic profile is linked to a lower risk of estrogen receptor-negative breast cancer and female genital tract polyps.
What this genotype means: Elevated risk of prostate cancer; Elevated risk of liver cancer in cirrhosis; Lower risk of ER-negative breast cancer.
Sample genotype (not yours): A/A
Higher Breast Cancer Risk but Lower Prostate Risk
Carrying two copies of the minor A allele presents a distinct trade-off, raising the risk of breast cancer while lowering the risk of prostate and liver cancers. This profile is also linked to longer average telomere length.
What this genotype means: Elevated risk of ER-negative breast cancer; Reduced risk of prostate and liver cancer; Slightly increased risk of female genital polyps.
Sample genotype (not yours): G/A
Typical Cancer Susceptibility
Carrying one copy of each allele results in intermediate telomerase activity and typical baseline risks for various cancers. This heterozygous profile balances the risks and protective factors associated with both the G and A alleles.
What this genotype means: Typical baseline risk for prostate cancer; Typical baseline risk for breast cancer; Typical baseline risk for liver cancer.
Gene function and biological role
Gene Function: The TERT gene encodes the catalytic subunit of telomerase, a specialized polymerase enzyme essential for maintaining chromosomal stability [1]. Telomerase adds repetitive DNA sequences to the ends of chromosomes, known as telomeres, preventing cellular senescence and genetic degradation [1]. Highly active in stem cells and germline tissues, this enzyme is typically suppressed in mature somatic cells to prevent uncontrolled proliferation [2]. However, aberrant reactivation or altered expression of this gene is a hallmark of many human malignancies, driving cellular immortality [3].
Variant Impact: Located in an intron of the TERT gene, this single nucleotide polymorphism influences gene splicing and expression levels [1]. The genetic variation alters the balance of functional telomerase reverse transcriptase, affecting telomere maintenance and cellular lifespan [1]. Research associates this specific change with divergent susceptibility to several cancer types, depending on the tissue [3]. While one allele is linked to elevated risks of certain hormone-related or epithelial cancers, the other allele is associated with increased risks of urogenital and gastrointestinal malignancies [4].
Key Insight: This variant represents a genetic trade-off where the allele that protects against prostate and liver cancers simultaneously increases the risk of breast cancer.
Location: TERT. Chromosome 5 · 5p15.33 · 1.3 Mb
Estimated prevalence by population
Global 68.0%; European 64.6%; African 75.3%; East Asian 68.2%; South Asian 67.0%; Americas 71.4%; Ashkenazi 61.2%; Finnish 60.0%; Middle Eastern 66.1%; Amish 60.5%.
Estimated GG genotype frequency.
Global 28.8%; European 31.6%; African 22.9%; East Asian 28.8%; South Asian 29.7%; Americas 26.2%; Ashkenazi 34.1%; Finnish 34.9%; Middle Eastern 30.4%; Amish 34.6%.
Estimated GA genotype frequency.
Global 3.2%; European 3.9%; African 1.7%; East Asian 3.0%; South Asian 3.3%; Americas 2.4%; Ashkenazi 4.7%; Finnish 5.1%; Middle Eastern 3.5%; Amish 5.0%.
Estimated AA genotype frequency.
Showing effects for G/G genotype
Cancer & Oncology
Prostate Cancer
Prostate Cancer. Evidence: 10/10. Source: PMID 21743467. ~1.16x Risk.
Gastrointestinal Cancers
Liver Cancer. Evidence: 4/10. Source: PMID 35788059. ~1.64x Risk.
Breast Cancer
Breast Cancer. Evidence: 8/10. Source: PMID 27117709. Lower Risk.
Urologic Cancers
Bladder Cancer. Evidence: 8/10. Source: PMID 39024449. Increased Risk.
Endocrine & Reproductive
Female Reproductive Health & Fertility
Genital Tract Polyps. Evidence: 6/10. Source: PMID 39986329. Lower Risk.
Hormone Levels & Endocrine Regulation
Nontoxic Goiter. Evidence: 8/10. Source: PMID 39024449. Lower Risk.
Showing effects for A/A genotype
Prostate Cancer. Evidence: 10/10. Source: PMID 21743467. Lower Risk.
Liver Cancer. Evidence: 4/10. Source: PMID 35788059. Lower Risk.
Breast Cancer. Evidence: 8/10. Source: PMID 27117709. Increased Risk.
Bladder Cancer. Evidence: 8/10. Source: PMID 39024449. Lower Risk.
Genital Tract Polyps. Evidence: 6/10. Source: PMID 39986329. ~1.06x Risk.
Nontoxic Goiter. Evidence: 8/10. Source: PMID 39024449. Increased Risk.
Showing effects for G/A genotype
Prostate Cancer. Evidence: 10/10. Source: PMID 21743467. Typical Risk.
Liver Cancer. Evidence: 4/10. Source: PMID 35788059. Typical Risk.
Breast Cancer. Evidence: 8/10. Source: PMID 27117709. Typical Risk.
Bladder Cancer. Evidence: 8/10. Source: PMID 39024449. Typical Risk.
Genital Tract Polyps. Evidence: 6/10. Source: PMID 39986329. Typical Risk.
Nontoxic Goiter. Evidence: 8/10. Source: PMID 39024449. Typical Risk.
What this genotype means for the people who carry it
Sample genotype: GG (Homozygous)
Cellular mechanisms linked to this genotype tend to favor pathways that increase susceptibility to specific solid tumors, particularly prostate and liver cancers [1] [2]. Large-scale genome-wide association studies demonstrate a consistently elevated risk of prostate cancer, with an odds ratio of approximately 1.16 [3]. In patients with alcohol-related cirrhosis, this genetic profile significantly elevates the risk of developing hepatocellular carcinoma [4]. Bladder cancer risk is also higher compared to carriers of the minor allele [5]. However, the same cellular environment appears protective against estrogen receptor-negative breast cancer [6]. Maintaining routine cancer screenings and a healthy lifestyle can help manage these inherited risks.
Elevated risk of prostate cancer; Elevated risk of liver cancer in cirrhosis; Lower risk of ER-negative breast cancer.
Sample genotype: AA (Homozygous)
Genetic studies show that this homozygous minor genotype is strongly associated with longer leukocyte telomeres [1]. While longer telomeres are generally linked to slower cellular aging, they also provide a longer replicative lifespan for cells, which can increase the risk of certain cancers like estrogen receptor-negative breast cancer [2] [3]. Conversely, this genetic makeup is highly protective against prostate cancer, significantly reducing susceptibility [4]. It also offers substantial protection against hepatocellular carcinoma, particularly in individuals with alcohol-related liver disease [5]. Other minor associations include a slightly increased risk of benign growths like female genital tract polyps and lipomas [6].
Elevated risk of ER-negative breast cancer; Reduced risk of prostate and liver cancer; Slightly increased risk of female genital polyps.
Sample genotype: GA (Heterozygous)
Having a balanced genetic profile at this locus means telomerase expression and telomere maintenance operate at typical baseline levels [1]. Statistical analyses show that heterozygous individuals do not experience the highly elevated risks of prostate or liver cancer seen with the G/G genotype [2] [3]. Similarly, the elevated risk of estrogen receptor-negative breast cancer associated with the A/A genotype is not observed here [4]. This intermediate state represents the most common genetic configuration across many populations. General wellness practices, including a balanced diet and regular exercise, remain the most effective ways to support cellular health. Routine medical checkups should follow standard age-appropriate guidelines.
Typical baseline risk for prostate cancer; Typical baseline risk for breast cancer; Typical baseline risk for liver cancer.
Variants with shared genetic architecture
rs2735940 · TERT Gene · Chr 5 · Colorectal Cancer Risk
rs2853677 · TERT Gene · Chr 5 · Cancer Susceptibility
rs7705526 · TERT Gene · Chr 5 · Lung Cancer Risk
Pan-cancer study detects genetic risk variants and shared genetic basis in two large cohorts.
Association analyses of more than 140,000 men identify 63 new prostate cancer susceptibility loci.
Diversity and scale: Genetic architecture of 2068 traits in the VA Million Veteran Program.
Identification of four novel susceptibility loci for oestrogen receptor negative breast cancer.
Content updated August 2026.
ReadYourDNA provides educational interpretation of DNA data you already have. It is not diagnostic, not a substitute for professional medical advice, diagnosis, or treatment, and is not intended to diagnose, treat, cure, or prevent any disease. Talk to a clinician before acting on any result.
Raw DNA Data Reports for 23andMe & AncestryDNA · About ReadYourDNA · FAQ · Methodology & Science · Pricing · Support and complaints · Legal & Contact · Health Traits · Pharmacogenomics · Carrier Status · Variant Explorer · The Human Karyotype · Privacy Policy · Terms of Service · Accessibility · Consumer Health Data Privacy · Your Privacy Choices · Editorial Standards · Your Data, Checkable · Sample Report · ReadYourDNA and Promethease compared · What is inside a 23andMe raw data file · What is inside an AncestryDNA raw data file · What a chatbot can and cannot do with your raw DNA file · Where a raw DNA file can still be uploaded in 2026
Written, maintained and operated by Martin Pechhacker, sole proprietor, Vienna, Austria. Trade register GISA 40064420. support@readyourdna.com