Method, system and probe set for determining site combination for detecting unstable state of microsatellite

Abstract

The invention discloses a method, a system and a probe set for determining a site combination for detecting an unstable state of a microsatellite. The method is a method which uses a single tumor sample and is based on a next-generation sequencing technology, and comprises the following steps: (1) preliminarily screening to obtain a candidate site set consisting of a plurality of microsatellite sites; and (2) calculating the contribution degree of each microsatellite locus in the candidate locus set to the MSI state, sorting the microsatellite loci in the candidate locus set according to the contribution degree, forming a screening locus set by using the microsatellite loci with the top n ranks, and calculating the sample MSI scores of the two groups of samples MSI-H and MSS by using the screening locus set, and obtaining a required site combination according to the sample score. The site combination disclosed by the invention not only can improve the accuracy and sensitivity of microsatellite state detection, but also greatly reduces the detection cost of a single sample process.

Description

technical field [0001] The invention relates to the field of gene detection, in particular to a site combination method, system and probe set for determining microsatellite instability. Background technique [0002] Microsatellites are uniformly distributed, short tandem repeats or simple repeats in eukaryotic genomes, generally composed of tandem repeat units of 1-6 nucleotides. If the mismatch repair (MMR) gene is mutated, it will not be able to repair the spontaneous high-frequency length variation in microsatellites in time, thus causing microsatellite instability (MSI), that is, microsatellite instability (MSI) caused by the failure of the DNA mismatch repair system. Insertion or deletion of repetitive sequences in satellite regions. [0003] In 2017, the FDA approved pembrolizumab for the treatment of patients with dMMR / MSI-H unresectable or metastatic solid tumors, and MSI became the world's first molecular marker to guide tumor immunotherapy. MSI is present in a va...

AI Technical Summary

Problems solved by technology

However, paired samples are required, and the number of gene combinations detected by it is small, the throughput is low, and specific gene mutation information cannot be provided.

In the judgment of the results, problems such as too strong or too little fluorescence, non-specific peaks, insignificant peak size changes, and loss of heterozygosity will be encountered.

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