rs1800462
A SNP in the TPMT gene on chromosome 6. Its most notable genotype is G;G: incapable of detoxifying certain drugs
- Gene
- TPMT
- Location
- Chr 618,143,724 (GRCh38)
- Highest magnitude
- 3.5Important
- Tested on
- 23andMe, AncestryDNA
- Minor allele frequency
- <1%
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
- G;GMost notableBadincapable of detoxifying certain drugs
- C;GBaddetoxifying ability of certain drugs may be diminished
- C;CGoodnormal for 23andMe
SNPedia records rs1800462 on the minus strand: (C;C), (C;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Other TPMT SNPs
- rs1142345C;Cpossibly incapable of detoxifying certain drugsImportant
- rs1800460T;Tincapable of detoxifying byproducts of certain drugsImportant
- rs1800584T;TTPMT*4A homozygote; likely issues detoxifying certain drugsImportant
- rs56161402T;TTPMT*8 homozygote; likely issues detoxifying certain drugsWorth knowing
- rs2842951C;Ccommon in complete genomicsTypical
Notes
From SNPedia
Show notes, about 180 words
rs1800462, also known as A80P, is a rare SNP in the TPMT gene, potentially encoding a variant incapable of detoxifying byproducts of certain antineoplastic and immunosuppressant drugs. In general, individuals must have two nonfunctioning TPMT alleles for the toxicity to be pronounced. The risk allele for this SNP (in orientation to the dbSNP entry) is rs1800462(C), and it encodes the TPMT*2 allele. It may occur at a frequency of 1 in 200 alleles among Caucasians. wikipedia thiopurine drugs metabolized by TPMT include azathioprine, mercaptopurine, and thioguanine
G;G
poor drug metabolism of some medications. potentially encoding a variant incapable of detoxifying byproducts of certain antineoplastic and immunosuppressant drugs. http://blog.23andme.com/health-traits/do-you-know-how-youll-respond-to-thiopurine-medications/
C;G
a carrier for rs1800462(G;G) which may may be diminish your detoxifying ability for Thiopurine medications. http://blog.23andme.com/health-traits/do-you-know-how-youll-respond-to-thiopurine-medications/
C;C
appears common for 23andMe users
Source and license
Adapted from rs1800462 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 Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice.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.