A single-sample microsatellite instability analysis method and device for pan-cancer species

Abstract

The present application discloses a single-sample microsatellite instability analysis method and device for pan-cancer species. The method of the present application includes obtaining the sample to be tested whose average depth of the MSI site in the chip capture interval meets the quality control requirements; filtering the site according to the number of site repetitions, depth, effective statistics, and site discrimination in the reference genome; The product of the non-reference ratio and the non-parameter entropy is used as the MSI statistic, and the normalized Zscore value of the sample to be tested relative to the MSS statistic distribution is used as the site MSI score; the weighted average of the site MSI score is used as the sample MSI score; Finally, the MSI status was judged according to the number of valid sites in the baseline site and the threshold of the sample MSI score. The method of the present application can accurately and effectively perform MSI analysis based on a single sample, overcomes the detection defect of single sample analysis, and the obtained result is highly consistent with the microsatellite instability result of the gold standard PCR detection analysis.

Description

technical field [0001] The present application relates to the technical field of microsatellite instability analysis of pan-cancer species, in particular to a single-sample microsatellite instability analysis method and device for pan-cancer species. Background technique [0002] A microsatellite locus is a short tandem repeat sequence, which is described by the two dimensions of repeat unit and repeat number. The repeat number of microsatellite loci is generally 5 to 50 times. Microsatellite instability (MicrosatelliteInstability, MSI) is one of the important molecular characteristics of tumors. The state of microsatellite loci is generally divided into two types: MSI-H (MSI High) represents an unstable state, MSS (Microsatellite Stable) represents a stable state, and tumors in the two states are resistant to immune checkpoint inhibitors (immune checkpoint inhibitors, ICIs). ) There were significant differences in drug response rates. MSI-H is more common in colorectal ca...

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Problems solved by technology

[0004] The significant difference between single-sample MSI analysis and paired-sample MSI analysis is that paired-sample analysis can exclude germline variation sites in patients through control samples, and only retain systemic variation sites for MSI analysis, while single-sample MSI analysis cannot distinguish germline and Systemic variation site

However, in clinical applications, there are often cases where there is no control sample, and paired sample MSI analysis cannot be performed, and only single-sample MSI analysis can be performed; however, the MSI obtained by single-sample MSI analysis cannot distinguish germline and systemic variant sites. The accuracy and validity of the analysis results are greatly affected

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