{{Rsnum
|rsid=1800462
|Gene=TPMT
|Chromosome=6
|position=18143724
|Orientation=minus
|GMAF=0.003673
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(C;C)
|geno2=(C;G)
|geno3=(G;G)
|Gene_s=TPMT
}}{{CPMC SNP
|link=https://cpmc.coriell.org/Sections/Results/TPMT.aspx?pgId=221
}}[[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.

[[http://en.wikipedia.org/wiki/Thiopurine_methyltransferase| wikipedia]] thiopurine drugs metabolized by TPMT include [[azathioprine]], [[mercaptopurine]], and [[thioguanine]]

{{PharmGKB
|RSID=rs1800462
|Name_s=TPMT*2, TPMT:238G>C
|Gene_s=TPMT
|Feature=Exon
|Evidence=PubMed ID:7862671
|Annotation=The TPMT:238G>C SNP was cloned from a patient with severe mercaptopurine toxicity. It results in a non-synonymous protein change TPMT:Ala80Pro that has a 100-fold reduction in catalytic activity compared to wild type when expressed in yeast.
|Drugs=mercaptopurine
|Drug Classes=
|Diseases=
|Curation Level=Curated
|PharmGKB Accession ID=PA162372520
}}

{{PharmGKB
|RSID=rs1800462
|Name_s=TPMT*2
|Gene_s=TPMT
|Feature=Exon
|Evidence=PubMed ID:15228163
|Annotation=Carriers of this variant have low, no, or intermediate (in the case of heterozygotes) TPMT activity, putting them at risk for hematologic toxicity if treated with thiopurines.
|Drugs=azathioprine; mercaptopurine
|Drug Classes=
|Diseases=
|Curation Level=Curated
|PharmGKB Accession ID=PA162263519
}}

{{PharmGKB
|RSID=rs1800462
|Name_s=TPMT*2
|Gene_s=TPMT
|Feature=Exon
|Evidence=Web Resource:http://www.pharmgkb.org/search/annotatedGene/tpmt/variant.jsp
|Annotation=Carriers of this variant have low, no, or intermediate (in the case of heterozygotes) TPMT activity, putting them at risk for hematologic toxicity if treated with thiopurines.
|Drugs=azathioprine; mercaptopurine
|Drug Classes=
|Diseases=
|Curation Level=In-Depth
|PharmGKB Accession ID=PA162359960
}}

{{omim
|id=187680
|rsnum=1800462
|variant=0001
}}

{{ClinVar
|rsid=1800462
|Reversed=1
|FwdREF=G
|FwdALT=C
|REF=C
|ALT=G
|RSPOS=18143955
|CHROM=6
|GMAF=0.0037
|dbSNPBuildID=89
|SSR=0
|SAO=1
|VP=0x050368000000040116110100
|GENEINFO=TPMT:7172
|GENE_NAME=TPMT
|GENE_ID=7172
|WGT=0
|VC=SNV
|CLNALLE=1
|CLNHGVS=NC_000006.11:g.18143955C>G
|CLNSRC=GTR; OMIM Allelic Variant
|CLNORIGIN=1
|CLNSRCID=GTR000500004; 187680.0001
|CLNSIG=6
|CLNCUI=C0342801; CN077959\x2cCN077995\x2cCN078017
|CLNDBN=Thiopurine methyltransferase deficiency
|Disease=Thiopurine methyltransferase deficiency
|CLNACC=RCV000013558.1
|Tags=RV;PM;PMC;S3D;SLO;VLD;GNO;KGPhase1;KGPROD;OTHERKG;LSD;OM
|CAF=0.9963; 0.003673
|CLNDSDB=MedGen:OMIM:SNOMED_CT
|CLNDSDBID=C0342801:610460:238012003
|COMMON=1
}}

{{PMID Auto
|PMID=18547414
|Title=Genotyping panel for assessing response to cancer chemotherapy.
|OA=1
}}

{{PMID Auto
|PMID=18685564
|Title=Genetic polymorphism of inosine triphosphate pyrophosphatase is a determinant of mercaptopurine metabolism and toxicity during treatment for acute lymphoblastic leukemia.
|OA=1
}}

{{PMID Auto
|PMID=22385887
|Title=High prevalence of polymorphism and low activity of thiopurine methyltransferase in patients with inflammatory bowel disease.
}}

{{PMID Auto
|PMID=23133420
|Title=Pharmacogenomic Diversity among Brazilians: Influence of Ancestry, Self-Reported Color, and Geographical Origin.
|OA=1
}}

{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}