[Detection of UGT1A1*6 single nucleotide polymorphism in oral swap samples using the cascade invader assay-based...

The adverse reaction to irinotecan is related to the single nucleotide polymorphism (SNP) of UGT1A1*6 genotype. The current SNP detection methods have various disadvantages, including time-consuming procedures, high- risk cross-contamination, and cumbersome operation. Hence, it is necessary to establish a new method suitable for clinical application, which is easy and simple to detect SNP with minimal risk for cross-contamination. In this study, a cascade invader assay-based real-time PCR, for UGT1A1*6 genotyping has been established by optimizing reaction conditions with DNA samples of three genotypes. The sensitivity and accuracy of the method were evaluated with DNAs derived from oral swab samples. The results showed that the method could detect the UGT1A1*6 genotypes from the oral swab samples with a detection limit of 6 ng genomic DNA with 100% accuracy. Due to its convenient and non-invasive sampling, single close-tube operation, and minimal risk for cross-contamination, the method has the potential in clinical application for individualized detection of drug-related UGT1A1*6 polymorphism and reaction to irinotecan.