MICROSATELLITE INSTABILITY DETECTION METHOD BASED ON SECOND-GENERATION SEQUENCING

A microsatellite instability detection method based on second-generation sequencing. The method comprises the following steps: (1) merging sequencing data of different MSI negative samples, so as to obtain a reference set; (2) compiling statistics on the depths Di of MSI sites i in the reference set; (3) calculating a data feature Fi of a microsatellite sequence of the MSI sites i of the MSI negative samples; (4) compiling statistics, in the entire reference set, on the number of the depths Di of MSI sites i that have a value lower than a threshold value a, and then performing selection and constructing a hybrid reference set; (5) performing, in groups, quality control on the MSI negative samples; (6) performing a first instance of detection; (7) if the number of sites j that are determined to be MSS candidate sites during the first instance of detection is less than d, taking a result of the first instance of detection as a final detection result, otherwise, performing a second instance of detection to obtain a final detection result; and (8) on the basis of a proportion of the number, which is obtained in step (7), of sites j that are determined to be MSI candidate sites in samples to be detected in the total number of sites of said sample, determining the microsatellite stability of said sample.