BACKGROUND The thiopurine drugs azathioprine and 6-mercaptopurine are well established in the treatment of inflammatory bowel disease (IBD). However, great interpatient variability exists in the efficacy and toxicity of the drugs, and this results from thiopurine methyltransferase (TPMT) gene polymorphisms. The aim of this study was to identify the TPMT gene polymorphisms in Chinese IBD patient...

Azathioprine (AZA) is a commonly used immunosuppressant for systemic lupus erythematosus (SLE). Myelosuppression is a serious adverse reaction due to AZA and its metabolites. Thiopurine S-methyltransferase (TPMT) is the rate-limiting enzyme. Variations of TPMT enzyme activity may be responsible for myelosuppression. However, a correlation between certain mutant alleles of low TPMT enzyme activi...

Thiopurine induced toxicity is associated with defects in the thiopurine methyltransferase (TPMT) gene. TPMT is a polymorphic enzyme, with most of the single nucleotide polymorphisms (SNPs) causing an amino acid change, altering the enzymatic activity of the TPMT protein. In this study, we characterize a novel patient allele c.719A > C, named TPMT*41, together with the more common variant *3C c...

Thioguanine and mercaptopurine are prodrugs requiring conversion into thiopurine nucleotides to exert cytotoxicity. Thiopurine S-methyltransferase (TPMT), an enzyme subject to genetic polymorphism, catabolizes thiopurines into inactive methylated bases, but also produces methylthioguanine nucleotides and methylmercaptopurine nucleotides from thioguanine and mercaptopurine nucleotides, respectiv...

BACKGROUND & OBJECTIVE Mercaptopurine, azathioprine, and thioguanine, used as antineoplastic agents and immunosuppressants are catabolized by thiopurine methyltransferase (TPMT) enzyme, which exhibits genetic polymorphism. Genotyping patients and the population to which the patients belong, is important for effective treatment and reducing toxicity. There is a need for faster methods for genoty...

BACKGROUND Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme that catalyses the S-methylation of 6-mercaptopurine and azathioprine. Low activity phenotypes are correlated with polymorphism in the TPMT gene. Patients with low or undetectable TMPT activity could develop severe myelosuppression when they are treated with standard doses of thiopurine drugs. Since ethnic differences in the...

A 62-year-old Chinese patient with recurrent pompholyx submitted his blood sample for pre-treatment thiopurine S-methyltransferase (TPMT) pharmacogenetic profiling, and it was found to harbour a novel single nucleotide polymorphism (SNP). The novel SNP, detected by mRNA sequencing, was a c.2T>C (g.11018T>C) transition in the start codon, causing a Met1Thr amino acid change. This finding was con...

Thiopurine S-methyltransferase (TPMT) is an enzyme that converts thiopurine drugs into inactive metabolites. Over 20 variant TPMT-encoding alleles, which cause reduced enzymatic activity, have been discovered so far. Our aim was to investigate the frequencies of variant alleles, i.e. genotypes in inflammatory bowel disease (IBD) patients and healthy individuals and to compare these frequencies ...

BACKGROUND AND AIMS The thiopurine drugs, azathioprine (AZA) and 6-mercaptopurine, are established in the treatment of inflammatory bowel diseases (IBD). Polymorphisms in thiopurine S-methyltransferase (TPMT) gene have been associated with adverse drug reactions (ADRs) to AZA. METHODS The aim of this study was to evaluate TPMT polymorphisms and AZA-related toxicity in a Slovak cohort of 220 I...

The drug-metabolizing enzyme thiopurine methyltransferase (TPMT) has become one of the best examples of pharmacogenomics to be translated into routine clinical practice. TPMT metabolizes the thiopurines 6-mercaptopurine, 6-thioguanine, and azathioprine, drugs that are widely used for treatment of acute leukemias, inflammatory bowel diseases, and other disorders of immune regulation. Since the d...