Studies examining the prevalence of MMR mutations among EC tumors show that it ranges between 2% and 5.9%.8, 9, 10, 11, 12, 13, 14 When patients with ovarian cancer are also included, a study of over 580 patients at the University of Hospital of Dresden, by Kast et al, estimated the rate of pathogenic germline mutations to be of only 0.3%.15 A study conducted by Dillon et al14 showed that 2.1% (5/233) of EC patients were identified to have LS, with germline MMR mutations; 1.3% (3/233) patients were found to have Lynch‐like syndrome,14 negative for germline MMR mutations. The gene discussed is MRC1; the disease is Leigh syndrome.