Systems and methods for determining microsatellite instability

A computer-implemented method, comprising:

• acquiring, using a microprocessor, genomic reference sequence data from a plurality of reference biological samples corresponding to respective individuals;
• analyzing the reference sequence data to generate a distribution of sequences at each of a plurality of microsatellite regions;
• determining ethnic group variability of the distribution at each of the plurality of microsatellite regions for the plurality of reference biological samples, the ethnic group variability including genomic sequence differences;
• identifying ethnically biased microsatellite regions of the plurality of microsatellite regions based on the ethnic group variability at each of the plurality of microsatellite regions;
• and
• generating a reference sample dataset by removing or filtering the ethnically biased microsatellite regions from the reference sequence data of the plurality of reference biological samples.

A sequencing device configured to acquire tumor sequence data of a tumor sample, comprising:

• a memory device including executable application instructions stored therein;
• and
• a processor configured to execute the application instructions stored in the memory device, wherein the application instructions comprise instructions that cause the processor to:
• receive the tumor sequence data from sequencing device;
• identify a distribution of a plurality of microsatellite regions in the tumor sequence data;
• determine that the tumor sample is not associated with a matched normal sample;
• access reference sequence data;
• determine a microsatellite instability type of the tumor sample based on a comparison of the distribution of the tumor sample to a reference distribution of the reference sample dataset;
• and
• provide an indication of a treatment option based on a determination that the tumor sample is a microsatellite instability high type.