UGT1A1 Genotyping for Irinotecan Toxicity

  • Print
  • Email

Irinotecan (CPT-11) is a common chemotherapeutic drug used for the treatment of advanced colorectal and gastric cancer. Allelic variance of UGT1A1 may be associated with increased drug toxicity and with syndromes such as Gilbert syndrome (benign familial hyperbilirubinemia) and Crigler-Najjar (rare form of nonhemolytic jaundice).

The Life-Daan JV Diagnostic Kit For UGT1A1 Genotyping is an sequencing base assay for determining the genotype(s) of UGT1A1.


It can detect the polymorphic TA repeat in the TATA element of the 5’-promoter region of UGT1A1, and a G>A mutation at nucleotide 211 in exon 1 of UGT1A1. Testing for UGT1A1 genotype before initiating irinotecan therapy is recommended so initial doses can be adjusted.

【FDA Guidance】

In 2005, the FDA made changes to the labeling of irinotecan to add pharmacogenomics recommendations, such that irinotecan recipients with a homozygous (both of the two gene copies) polymorphism in UGT1A1 gene, to be specific, the *28 variant, should be considered for reduced drug doses. Irinotecan is one of the first widely used chemotherapy agents that is dosed according to the recipient's genotype.


  • Low–input DNA protocol (20 ng), compatible with serum/plasma samples
  • Technology: Sanger Sequencing
  • Test results for research use only, cannot be taken as the basis of clinical diagnosis.

【How It Works】

  • Amplification of relevant portions of the UGT1A1 promoter region, and the nucleotide 211 in exon 1 ;
  • Gene sequencing with 3500Dx and 3500Dx XL Genetic Analyzer of purified products;
  • Computer analysis to determine mutation presence or absence.

【Applicable population】

  • Patient who will receive irinotecan, who has a history of irinotecan sensitivity
  • Patient who experiences neutropenia while receiving irinotecan