rs28371685

A SNP in the CYP2C9 gene on chromosome 10. Its most notable genotype is T;T: CYP2C9*11 homozygote

Gene
CYP2C9
Location
Chr 1094,981,224 (GRCh38)
Highest magnitude
2.5Worth knowing
Tested on
23andMe, AncestryDNA, FamilyTreeDNA
Minor allele frequency
<1%

Genotypes

As shown in 23andMe and AncestryDNA files.

  1. C;CGoodnormalTypical · 0.089% of people
  2. C;TNot ratedcarrier of one CYP2C9*11 alleleTypical · 0.011% of people
  3. T;TMost notableBadCYP2C9*11 homozygoteWorth knowing · 2.50% of people

On SNPedia: (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 5 HapMap populations.

  • AverageC;C 89% C;T 11% T;T 0%
  • Japanese (Tokyo)C;C 99% C;T <1% T;T 0%
  • African ancestry (Southwest US)C;C 96% C;T 4% T;T 0%
  • Gujarati IndianC;C 99% C;T 1% T;T 0%
  • Luhya (Kenya)C;C 96% C;T 4% T;T 0%
  • Maasai (Kenya)C;C 54% C;T 46% T;T 0%

Other CYP2C9 SNPs

All CYP2C9 SNPs

Genosets

Genosets combine several genotypes. Twofold checks them in your report.

Notes

From SNPedia

Notes

rs28371685, also known as 1003C>T, 42542C>T or R335W is a SNP in the CYP2C9 gene. The rs28371685(T) allele defines the CYP2C9*11 variant, which has decreased activity. According to a 23andMe discussion This is one of the SNPs which were re-analyzed April 2009. Customers with older data may wish to redownload. SNPs effected rs4420638, rs34276300, rs3091244, rs34601266, rs2033003, rs7900194, rs9332239, rs28371685, rs1229984, and rs28399504.

Source and license

Adapted from rs28371685 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.