rs3218536

A SNP in the XRCC2 gene on chromosome 7. Its most notable genotype is T;T: lower risk for breast, ovarian cancer

Gene
XRCC2
Location
Chr 7152,648,922 (GRCh38)
Highest magnitude
2.0Worth knowing
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
4%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. T;TMost notableGoodlower risk for breast, ovarian cancerWorth knowing · 2.0<1% of people
  2. C;TGoodlower risk for breast, ovarian cancerWorth knowing · 2.010% of people
  3. C;CNot ratednormal riskTypical · 0.090% of people

SNPedia records rs3218536 on the minus strand: (A;A), (A;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.

Frequency

Share of each genotype in 9 HapMap populations.

  • AverageT;T <1% C;T 10% C;C 90%
  • European ancestry (Utah)T;T <1% C;T 18% C;C 81%
  • Han Chinese (Beijing)T;T 0% C;T 0% C;C 100%
  • Japanese (Tokyo)T;T 0% C;T 0% C;C 100%
  • Yoruba (Nigeria)T;T 0% C;T 0% C;C 100%
  • African ancestry (Southwest US)T;T 0% C;T 11% C;C 90%
  • Gujarati IndianT;T 1% C;T 21% C;C 78%
  • Mexican ancestry (Los Angeles)T;T 0% C;T 10% C;C 90%
  • Maasai (Kenya)T;T 0% C;T 7% C;C 93%
  • TuscanT;T 0% C;T 21% C;C 79%

Conditions, medicines and genes

Other XRCC2 SNPs

All XRCC2 SNPs

Notes

From SNPedia

Notes

rs3218536, a relatively rare SNP also known as Arg188His located in the DNA-repair gene XRCC2, is associated with a lowered risk for breast cancer based on a study of 1,100 Cypriot women. The odds ratio for the His-encoding rs3218536(A) allele carriers is homozygote is 0.79, CI: 0.62-1.00, p=0.05. rs3218536(A) carriers also appear to be at lower risk for epithelial ovarian cancer. In a study of ~1,600 cases, the odds ratio for rs3218536(A;G) heterozygotes was 0.8 (CI: 0.7-1.0) and for the (quite rare) rs3218536(A;A) homozygotes 0.3 (0.1-0.9).

Source and license

Adapted from rs3218536 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.

SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.