MUTYH-associated polyposis (MAP) is an autosomal recessive cancer predisposition syndrome associated with the development of colorectal tumors and colonic polyps at an early age. MAP syndrome is associated to germline biallelic mutations in the MUTYH gene which lead to deficient DNA repair through the base-excision repair system and accumulation of G:C-T:A transversions. Occurrence of such mutations in oncogenes and tumor suppressor genes drives colorectal carcinogenesis and is associated with the development of colonic polyps. The aim of this study was to assess the frequency of germline MUTYH mutations in patients with MAP and other hereditary colorectal cancer (CRC) phenotypes. A total of 30 patients were included. Samples were screened for the MUTYH germline mutations by capillary array electrophoresis (HA_CAE) method. In all mutation-positive cases, results were confirmed by sequencing. Biallelic germline MUTYH mutations were identified in 2 of 30 (6.6%) patients with a phenotype of hereditary colorectal cancer. Besides, four monoallelic variants were detected in different samples that are described in LOVD database (MUTYH_00078, MUTYH_00005, MUTYH_00063, MUTYH_00086). A genotype-phenotype correlation has found in these patientns. Germline MUTYH mutation screening should be considered in the differential diagnosis of hereditary colorectal syndromes, we are considering the validity and applicability of MUTYH mutation screening in our population.

Resumen del póster presentado a la European Human Genetics Conference celebrada en Nuremberg (Alemania) del 23 al 26 de junio de 2012.

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