Two missense mutations in thiopurine S-methyltransferase (TPMT) with a minor allele frequency of 0.22 in the UC patients compared with a reported 0.062 in the Icelandic population were identified.
TPMT activity was measured by high performance liquid chromatography (HPLC) and genotypes for the 3 mentioned polymorphisms were determined in 215 unrelated UC patients and 212 unrelated healthy controls by polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) in a Kurdish population from Iran.
These siblings with active UC illustrate that skewed thiopurine metabolism may occur despite normal TPMT enzyme activity and can lead to adverse events in the absence of disease control.
ITPA(94C>A, IVS2+21A>C) and TPMT (238G>C, 460G>A, and 719A>G) genotypes were assessed in 262 IBD patients (159 females, 103 males; 67 patients with ulcerative colitis, 195 patients with Crohn's disease) treated with AZA and were correlated with the development of leukopenia and hepatotoxicity.
We have analyzed the frequencies of the allelic variants of the TPMT gene in a white European population of healthy blood donors from Spain and The Netherlands, and in a group of patients suffering from ulcerative colitis (UC) with a similar genetic background.