Ren et al. (2020) identified 10 LS patients among 211 Chinese EC patients, with the most common mutation being MSH6 (70%), followed by MSH2 mutations (20%). In our study, 9 cases of LS were detected in 90 EC patients, including 3 MLH1, 2 PMS2, 2 MSH2, and 2 MSH6 germline mutations. Among the 9 LS patients, 7 were classified as MMRd and 2 as NSMP. The routine screening method involves IHC for MMR proteins and further MLH1 methylation testing for patients with MLH1 loss, followed by germline mutation testing based on the results. This evidence concerns the gene PMS2 and Leigh syndrome.