The genetic testing for Lynch syndrome initiates with the immunohistochemistry (IHC)screening for expression of MLH1/MSH2/MSH6 and PMS2with concomitant microsatellite instability (MSI) analysis, using a panel ofpenta-quasi-monomorphic markers previously optimized by our group for the Brazilianpopulation (Campanella et al.,2014). This evidence concerns the gene MLH1 and Lynch syndrome.