rs6413438
A SNP in the CYP2C19 gene on chromosome 10. Its most notable genotype is T;T: CYP2C19*10 homozygote
- Gene
- CYP2C19
- Location
- Chr 1094,781,858 (GRCh38)
- Highest magnitude
- 3.0Important
- Tested on
- 23andMe, AncestryDNA, FamilyTreeDNA
Genotypes
As shown in 23andMe and AncestryDNA files.
- C;CGoodnormal
- C;TNot ratedcarrier of one CYP2C19*10 allele
- T;TMost notableNot ratedCYP2C19*10 homozygote
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 6 HapMap populations.
- AverageC;C 98% C;T 2% T;T 0%
- European ancestry (Utah)C;C 100% C;T 0% T;T 0%
- Han Chinese (Beijing)C;C 100% C;T 0% T;T 0%
- Japanese (Tokyo)C;C 100% C;T 0% T;T 0%
- Yoruba (Nigeria)C;C 100% C;T 0% T;T 0%
- Gujarati IndianC;C 92% C;T 8% T;T 0%
- Maasai (Kenya)C;C 97% C;T 3% T;T 0%
Related
Other CYP2C19 SNPs
- rs4244285A;Apoor metabolizer of several popular medicines; patients prescribed Plavix get less benefit, and have higher risk for adverse cardiovascular eventsVery important
- rs41291556C;CCYP2C19*8 homozygoteImportant
- rs56337013T;TCYP2C19*5 homozygoteImportant
- rs28399504G;Gpoor metabolizerWorth knowing
- rs4986893A;Apoor metabolizer of several commonly prescribed drugsWorth knowing
- rs12248560C;TCYP2C19*17 ultra fast metabolizer; drug metabolism effects; also 0.77x decreased breast cancer riskWorth knowing
- rs3758580C;Ccommon/normalTypical
- rs3758581A;ACYP2C19 V331I homozygoteTypical
Genosets
- Gs152CYP2C19 Poor MetabolizerImportant
- Gs151CYP2C19 Intermediate MetabolizerImportant
- Gs150CYP2C19 normal/rapid metabolizer (most likely)Minor
Genosets combine several genotypes. Twofold checks them in your report.
Notes
From SNPedia
Notes
The rs6413438(T) allele defines the CYP2C19 allele known as CYP2C19*10. This allele may lead to reduced metabolism of S-mephenytoin at least in vitro.
Source and license
Adapted from rs6413438 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.