Thiopurine S-Methyltransferase (TPMT) genotyping and phenotyping for predicting response to thiopurine drug therapy for Inflammatory Bowel Disease

Record ID 32010000879
Authors' objectives:

Thiopurine S-methyltransferase (TPMT) is an enzyme involved in the metabolism of drugs called thiopurines, such as the immunosuppressant azathioprine, used to treat inflammatory bowel disease (IBD). In the general population, there is wide variation in TPMT enzyme activity that is largely genetically determined by the TPMT gene. While normal levels of TPMT enzyme activity are found in 89% of people, 11% have intermediate activity and approximately 0.3% have little or no activity. People who lack TPMT enzyme activity generally cannot tolerate treatment with thiopurines and often develop severe bone marrow toxicity that can be life threatening. TPMT genotyping determines the most common TPMT gene alleles that result in intermediate or deficient levels of the TPMT enzyme. TPMT phenotyping determines the level of TPMT enzyme activity found in red blood cells. TPMT genotyping and phenotyping have the potential to be used as a screening test to identify IBD patients who are at an increased risk of bone marrow complications so that treatment decisions can be made before they are prescribed drugs that contain thiopurine.

Project Status: Completed
URL for project:
Year Published: 2009
English language abstract: An English language summary is available
Publication Type: Not Assigned
Country: United States
MeSH Terms
  • Inflammatory Bowel Diseases
  • Methyltransferases
  • Treatment Outcome
Organisation Name: HAYES, Inc.
Contact Address: 157 S. Broad Street, Suite 200, Lansdale, PA 19446, USA. Tel: 215 855 0615; Fax: 215 855 5218
Contact Name:
Contact Email:
Copyright: 2009 Winifred S. Hayes, Inc
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