rs28399504
A SNP in the CYP2C19 gene on chromosome 10. Its most notable genotype is G;G: poor metabolizer
- Gene
- CYP2C19
- Location
- Chr 1094,762,706 (GRCh38)
- Highest magnitude
- 2.5Worth knowing
- Tested on
- 23andMe, AncestryDNA, FamilyTreeDNA
- Minor allele frequency
- <1%
Genotypes
As shown in 23andMe and AncestryDNA files.
- A;AGoodnormal
- A;GNot ratedcarrier of a CYP2C19*4 allele, considered a "slow metabolizer" variant
- G;GMost notableBadpoor metabolizer
On SNPedia: (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 2 HapMap populations.
- AverageA;A 98% A;G 2% G;G 0%
- Han Chinese (Beijing)A;A 99% A;G 2% G;G 0%
- Mexican ancestry (Los Angeles)A;A 98% A;G 2% G;G 0%
Related
Conditions, medicines and genes
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
- rs41291556C;CCYP2C19*8 homozygoteImportant
- rs56337013T;TCYP2C19*5 homozygoteImportant
- 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
Show notes, about 130 words
rs28399504 is a SNP in the CYP2C19 gene, potentially encoding the CYP2C19*4 variant. This variant has been linked to poor metabolism of compounds like mephenytoin. It is also known as M1V or Met1Val. The risk allele is rs28399504(G). As a nonfunctioning CYP2C19, this variant would be expected to be a poor metabolizer of several commonly prescribed drugs, including anti-ulcer drugs like omeprazole (trade names Losec and Prilosec), esomeprazole (trade name Nexium), and lansoprazole (Prevacid). 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. Clopidogrel Efficacy
Source and license
Adapted from rs28399504 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.