rs3218005

A SNP in the CDKN2BAS gene on chromosome 9. Its most notable genotype is C;C: Slightly higher (1.55x) risk for breast cancer

Gene
CDKN2BAS
Location
Chr 922,000,248 (GRCh38)
Highest magnitude
1.5Minor
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
16%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. T;TGoodcommon/normalTypical · 0.065% of people
  2. C;TNot rated?Typical · 0.031% of people
  3. C;CMost notableBadSlightly higher (1.55x) risk for breast cancerMinor · 1.53% of people

SNPedia records rs3218005 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 4 HapMap populations.

  • AverageT;T 65% C;T 31% C;C 3%
  • European ancestry (Utah)T;T 83% C;T 15% C;C 2%
  • Han Chinese (Beijing)T;T 62% C;T 38% C;C 0%
  • Japanese (Tokyo)T;T 59% C;T 32% C;C 9%
  • Yoruba (Nigeria)T;T 57% C;T 40% C;C 3%

Conditions, medicines and genes

Other CDKN2BAS SNPs

All CDKN2BAS SNPs

Notes

From SNPedia

Notes

rs3218005 shows an association with breast cancer in a British study involving ~2300 patients. The odds ratio for the (G;G) vs (A;A) homozygotes is 1.55 (CI: 1.02-2.37, p=0.013). A common variant of the p16(INK4a) genetic region is associated with physical function in older people. Candidate gene analysis using imputed genotypes: cell cycle single-nucleotide polymorphisms and ovarian cancer risk. Chromosome 9p21 SNPs Associated with Multiple Disease Phenotypes Correlate with ANRIL Expression.

Source and license

Adapted from rs3218005 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.