dbMMR-Chinese database: the open-access database for variants in mismatch repair genes in Chinese population

Mutation in mismatch repair genes (MMR) is the genetic predisposition for gastrointestinal cancer represented by the Lynch Syndrome. Identification of the mutation carrier is critical in prevention and treatment of the cancer. Chinese is the largest ethnic population with the largestgastrointestinal cancer cases in the world, but systematic knowledge for the mutation in MMR is lack in Chinese population. Through comprehensive data mining, we collected nearly all MMR data derived from 33,998 Chinese of 23,938 cancer and 10,060 non-cancer cases reported from 1997 to 2019. Upon standardization and re-annotation, the data following international standards, we identified a total of 540 distinct MMR variants including 487 single base change and indel, and 53 large deletion/duplication in four MMR genes of MLH1, MSH2, MSH6and PMS2; 153 of the variants were classified as Pathogenic or Likely Pathogenic. This MMR dataset is the largest collection from a single, non-Caucasian population. We developed an open-access database, dbMMR-Chinese (https://dbMMR-chinese.fhs.um.edu.mo), to share with community for MMR mutation-related cancer study and clinical application.