What is XRCC3 (rs861539)? And Why Does the Toxin Zoomer Test for It?

Homologous recombination repair variant

XRCC3 (rs861539) is a single‑nucleotide variant in a gene that helps repair double‑strand DNA breaks through homologous recombination. It can influence how efficiently cells fix DNA damage from oxidative stress and chemical exposures. Testing this variant helps place toxicant measurements into genetic context by indicating potential differences in DNA‑repair capacity.

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XRCC3 (rs861539)

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About XRCC3 (rs861539)

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About XRCC3 (rs861539)

Overview and History

XRCC3 is a protein in the RAD51 family that participates in homologous recombination, a core pathway for repairing DNA double‑strand breaks and maintaining genomic stability. The rs861539 site is a common single‑nucleotide polymorphism that results in an amino‑acid change (often reported as Thr241Met) and has been studied for its effects on protein function and cellular repair activity. Since its description, rs861539 has been evaluated in population and laboratory studies for associations with variable DNA‑repair efficiency and altered cellular responses to genotoxic stress. While findings vary by study and population, the marker is useful as a genetic indicator of one component of cellular maintenance and response to environmental insults.

Interpreting Highs and Lows

For this SNP, “elevated” usually refers to presence of the variant allele and “low” to the common (wild‑type) allele. Presence of the variant allele has been associated in some studies with modest changes in DNA‑repair efficiency and altered handling of DNA damage after exposure to oxidants or chemical agents. The common allele is generally associated with typical XRCC3 function in study populations. These patterns are associative and not determinative; interpretation is most informative when combined with the full Toxin Zoomer report (toxicant levels, other detoxification genotypes, and clinical context).

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XRCC3 (rs861539) is included in the Toxin Zoomer to assess genetic contribution to DNA‑damage repair capacity. By comparing this variant with measured toxicant burden and other detoxification genotypes, clinicians get a clearer picture of how genetic repair tendencies might influence sensitivity to environmental exposures and monitoring priorities.

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XRCC3 (rs861539) FAQs

What is XRCC3 (rs861539) and why is it important?

XRCC3 (rs861539) is a common genetic variant in a DNA‑repair gene. It can be associated with small differences in how cells repair double‑strand DNA breaks caused by oxidative stress or chemical exposures. Knowing this variant helps put toxicant measurements into genetic context and may inform how an individual metabolically responds to environmental insults.

What does it mean if my XRCC3 (rs861539) levels are low?

If your result indicates the common (wild‑type) allele rather than the variant, it typically reflects typical XRCC3 function in study groups. That pattern is generally associated with standard repair efficiency in published associations. Interpretation should be made alongside your toxicant panel and other genetic markers, since overall sensitivity depends on multiple factors.

What does it mean if my XRCC3 (rs861539) levels are high?

If your result shows the variant allele, some studies link it to modestly altered XRCC3 function and differences in repairing DNA damage after exposures. This may suggest a tendency toward different cellular responses to genotoxic stress, but clinical significance depends on the full exposure and genetic profile and must be interpreted in context.

Why is XRCC3 (rs861539) included in the Toxin Zoomer?

XRCC3 rs861539 provides information about a core DNA‑repair pathway that interacts with environmental genotoxins. Measuring it alongside urinary toxicants and other detoxification genes helps clinicians identify patterns of vulnerability or resilience and supports more precise interpretation of an individual’s toxicant burden.

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