rs3803662

A SNP in the CASC16 gene on chromosome 16. Its most notable genotype is A;A: 1.6x increased risk for breast cancer

Gene
CASC16
Location
Chr 1652,552,429 (GRCh38)
Highest magnitude
3.0Important
Tested on
23andMe, AncestryDNA
Minor allele frequency
46%

Genotypes

Plus strand, as in 23andMe and AncestryDNA files.

  1. G;GGoodnormalTypical · 0.029% of people
  2. A;GNot rated?Typical · 0.045% of people
  3. A;AMost notableBad1.6x increased risk for breast cancerImportant · 3.025% of people

SNPedia records rs3803662 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 29% A;G 45% A;A 25%
  • European ancestry (Utah)G;G 58% A;G 35% A;A 7%
  • Han Chinese (Beijing)G;G 15% A;G 39% A;A 46%
  • Japanese (Tokyo)G;G 20% A;G 46% A;A 35%
  • Yoruba (Nigeria)G;G 21% A;G 48% A;A 30%
  • African ancestry (Southwest US)G;G 19% A;G 54% A;A 26%
  • Chinese (Denver)G;G 14% A;G 45% A;A 41%
  • Gujarati IndianG;G 55% A;G 37% A;A 9%
  • Luhya (Kenya)G;G 20% A;G 49% A;A 31%
  • Mexican ancestry (Los Angeles)G;G 36% A;G 47% A;A 17%
  • Maasai (Kenya)G;G 20% A;G 50% A;A 30%
  • TuscanG;G 45% A;G 47% A;A 8%

Conditions, medicines and genes

Notes

From SNPedia

Show notes, about 150 words

rs3803662, a SNP associated with the TNRC9 gene, was one of the four strongest associating SNPs found in a genome-wide association study of over 4,000 breast cancer samples. rs3803662(T;T) have a 1.64-fold greater risk of estrogen receptor-positive tumors In a study of 1,267 breast cancer patients, rs3803662 heterozygote carriers and minor allele homozygote carriers were more likely to be diagnosed before the age of 60 years (p = 0.025) relative to major allele homozygote carriers. breast cancer *rs2981582, rs3803662, and rs889312) showed weak but significant associations with ER-negative disease, the strongest association being for rs3803662 in TNRC9 (1.14 (1.09-1.21)) rs3803662 confirmed in 988 sporadic breast cancer cases and 1,016 controls from the West of Ireland to be associated with increased risk (odds ratio 1.15, p(allelic) = 5.1 x 10e-2) for breast cancer

Source and license

Adapted from rs3803662 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.