Rs1800462

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