rs41291556
A SNP in the CYP2C19 gene on chromosome 10. Its most notable genotype is C;C: CYP2C19*8 homozygote
- Gene
- CYP2C19
- Location
- Chr 1094,775,416 (GRCh38)
- Highest magnitude
- 3.0Important
- Tested on
- 23andMe, AncestryDNA, FamilyTreeDNA
- Minor allele frequency
- <1%
Genotypes
As shown in 23andMe and AncestryDNA files.
- C;CMost notableNot ratedCYP2C19*8 homozygote
- C;TNot ratedcarrier of one CYP2C19*8 allele, considered a "slow metabolizer"
- T;TGoodnormal
On SNPedia: (C;C), (C;T), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
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
- rs6413438T;TCYP2C19*10 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
Defines the CYP2C19 variant known as CYP2C19*8. Carriers of the rs41291556(C) allele may have decreased activity and poor metabolizer (PM) phenotype. This variant is associated with a dramatic (approximately 90% and 70%) reduction in the metabolism of S-mephenytoin and tolbutamide in vitro. Clopidogrel Efficacy
Source and license
Adapted from rs41291556 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.