Rapid recognition of aberrant dHPLC elution profiles using the Transgenomic NavigatorTM software

Abstract

Despite the availability of numerous technologies for detecting mutations, only a few have been formatted for automated mutation calling. Here, we evaluate the utility of the Transgenomic Navigator software to facilitate automated detection of aberrant denaturing high performance liquid chromatography (dHPLC) elution profiles. We used dHPLC to identify germline variants in MSH6, NEIL2, NEIL3, and OGG1 in 172 patients with multiple colorectal adenomas. 3,747 dHPLC profiles were analysed with the Navigator software using three levels of analysis, each differing in the degree of operator input. 43.5% (60/138) and 98.3% (59/60) of products with profiles distinct from wild type ('outliers') harboured novel variants under Level 1 and Levels 2/3 analysis conditions, respectively. We also assessed the utility of the software to rapidly detect samples carrying common polymorphisms by analysing regions of the genes that harbour polymorphisms with minor allele frequencies between 8 and 40%, therein analysing 2,784 profiles. We showed that 1573/1612 (97.6%) and 1137/1172 (97.0%) of PCR products were correctly classified as wild-type and variant, respectively (Level 3 analysis conditions). Finally, we assessed the utility of the software to detect novel variants in fragments that also harboured common polymorphisms and showed that 59/61 (96.7%) of products with profiles outlying both the wild type and polymorphism groups harboured novel variants. We conclude that the Navigator software provides an excellent tool for rapid discrimination of aberrant dHPLC elution profiles that harbour sequence variants.