rs3731239
A SNP in the CDKN2A gene on chromosome 9. Its most notable genotype is G;G: 0.9x lower risk for breast cancer
- Gene
- CDKN2A
- Location
- Chr 921,974,219 (GRCh38)
- Highest magnitude
- 0.0Typical
- Tested on
- 23andMe, AncestryDNA, FamilyTreeDNA
- Minor allele frequency
- 20%
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
SNPedia records rs3731239 on the minus strand: (C;C), (C;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Frequency
Share of each genotype in 11 HapMap populations.
- AverageG;G 4% A;G 22% A;A 74%
- European ancestry (Utah)G;G 16% A;G 50% A;A 34%
- Han Chinese (Beijing)G;G 2% A;G 16% A;A 82%
- Japanese (Tokyo)G;G 2% A;G 21% A;A 77%
- Yoruba (Nigeria)G;G 0% A;G 0% A;A 100%
- African ancestry (Southwest US)G;G 0% A;G 5% A;A 95%
- Chinese (Denver)G;G 2% A;G 25% A;A 73%
- Gujarati IndianG;G 11% A;G 46% A;A 44%
- Luhya (Kenya)G;G 0% A;G <1% A;A 99%
- Mexican ancestry (Los Angeles)G;G 3% A;G 16% A;A 81%
- Maasai (Kenya)G;G 0% A;G 8% A;A 92%
- TuscanG;G 7% A;G 51% A;A 42%
Related
Conditions, medicines and genes
Other CDKN2A SNPs
- rs1800586A;CPancreatic cancer/Melanoma SyndromeVery important
- rs36204594G;TPancreatic cancer/Melanoma SyndromeVery important
- rs104894098A;TPancreatic cancer/Melanoma SyndromeVery important
- rs121913381A;CPancreatic cancer/Melanoma SyndromeVery important
- rs199907548A;CPancreatic cancer/Melanoma SyndromeVery important
- rs587782206-;TGGCPancreatic cancer/Melanoma SyndromeVery important
- rs730881672-;CTPancreatic cancer/Melanoma SyndromeVery important
- rs730881675-;ACCCGTGCACGACGPancreatic cancer/Melanoma SyndromeVery important
Notes
From SNPedia
Notes
rs3731239 shows a slight protective association against breast cancer in a British study involving ~2300 patients. The odds ratio for the (C;C) vs (T;T) homozygotes is 0.90 (CI: 0.79-1.03, p=0.013). ovarian cancer rs3731239 rs602652 rs3212879 rs649392 rs3212891 rs2069391, rs2069414 rs17528736 rs3218036
Source and license
Adapted from rs3731239 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.