Rs56161402

rs56161402, also known as R215H or Arg215His, is a relatively rare SNP in the TPMT gene. This SNP potentially encodes 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 rs56161402(T), and it encodes the TPMT*8 allele (OMIM). This SNP was first identified in African-Americans.

[| wikipedia] thiopurine drugs metabolized by TPMT include azathioprine, mercaptopurine, and thioguanine