Validation of a genotyping method for analysis of TPMT polymorphisms

Clin Ther. 2012 Apr;34(4):878-84. doi: 10.1016/j.clinthera.2012.02.017. Epub 2012 Mar 14.

Abstract

Background: Thiopurine methyltransferase (TPMT) catalyzes the methylation of thiopurine drugs such as azathioprine and 6-mercaptopurine. Several mutations in the TPMT gene correlate with low enzyme activity and adverse effects such as myelotoxicity. Hence, genotyping TPMT makes it possible to identify patients at high risk for drug toxicity.

Objective: The aim of this study was to validate a TPMT genotyping method by comparing it with a conventional polymerase chain reaction (PCR) approach.

Methods: LightSNiP is a real-time PCR method for the detection of TPMT*2, *3B, and *3C without a sequencing step. We evaluated the frequencies of 3 TPMT alleles in 111 white adult patients by comparing genotyping by LightSNiP with conventional PCR (sequencing).

Results: No differences were observed between conventional genotyping with sequencing and LightSNiP for *2, *3B, and *3C, suggesting the validity of this method.

Conclusions: Compared with the conventional PCR sequencing method, the data suggest that LightSNiP correctly detected the TPMT *2, *3B, and *3C in this select population.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Base Sequence
  • DNA Primers
  • Genotype
  • Humans
  • Methyltransferases / genetics*
  • Polymerase Chain Reaction
  • Polymorphism, Genetic*

Substances

  • DNA Primers
  • Methyltransferases
  • thiopurine methyltransferase