Objective: To investigate the molecular deficiency in MMR genes associated to Lynch syndrome.
Material and methods: Immunohistochemical and microsatellite instability (MSI) analysis were performed in 5 families with suspected Lynch syndrome according to the clinical criteria, Amsterdam and/or Bethesda that had been treated at the Hospital Nacional Almanzor Aguinaga Asenjo (Lambayeque-Peru) during 2007-2010.
Results: The absence of expression of MLH1/PMS2 and high MSI (MSI-H) were observed in a male patient aged 60 with adenocarcinoma grade I. In addition, the point mutational analysis was performed in BRAF (V600E) to rule that it is a sporadic case of colorectal cancer. The absence of mutation in BRAF together with the molecular analysis suggests the suspicion as a Lynch syndrome.
Conclusions: It is the first molecular study reported in the Peruvian population and demonstrates the importance of molecular analysis in families with suspected hereditary colorectal cancer in order to provide possibilities of surveillance and monitoring that have been shown to reduce morbidity and mortality of colorectal cancer in the Peruvian population.