TPMT*3C Allele

**Semantic type:** Gene or Genome

**Definition:** Human TPMT*3C allele is located in the vicinity of 6p22.3 and is approximately 26 kb in length. This allele, a variant form of the TPMT wild-type allele, encodes thiopurine S-methyltransferase protein. TPMT*3C allele exhibits a clinically-relevant SNP (c.874A>G) that results in an Y240C coding change. This alteration in protein sequence decreases the enzymatic activity of the protein encoded by this allelic variant.

**Synonyms:** - TPMT, Y240C - TPMT, c.874A>G - TPMT-3C