Evaluation of germline alterations in MUTYH in patients with colorectal Cancer and KRAS G12C somatic mutation

• Grant number: 22/03407-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2022
• End date: December 31, 2022
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Giovana Tardin Torrezan
• Grantee: Ana Beatriz Deleame Medeiros
• Host Institution: A C Camargo Cancer Center. Fundação Antonio Prudente (FAP). São Paulo , SP, Brazil

Abstract

MUTYH-Associated Polyposis (MAP) is an autosomal recessive disease caused by alterations in the MUTYH gene, accounting for 0.7% of all colorectal cancers (CRC) and 13% of colorectal polyposis. The MUTYH gene is part of the DNA base excision repair system and, when mutated, leads to G:C - T:A transversions in several genes, including KRAS, often generating the somatic mutation c.34G>T; G12C in CRC of patients with MAP. This mutation occurs in less than 3% of patients with CRC, and previous studies have suggested its evaluation as a marker for the identification of patients with MAP. The aim of the study is to evaluate the detection rate of pathogenic/probably pathogenic germline variants (P/PP) in the MUTYH gene in patients with CRC and KRAS G12C somatic mutation. For this, tumor and leukocyte DNA will be extracted and 3 frequent P/PP variants of MUTYH will be evaluated through multiplex PCR and next-generation sequencing (NGS). Patients with only 1 heterozygous variant will be evaluated by complete sequencing of the MUTYH gene, and the results found will be described with descriptive statistics. We hope to verify whether patients with colorectal cancer and KRAS G12C somatic mutation have a higher risk of detection of P/PP germline variants in the MUTYH gene, evaluating the potential of this mutation to represent a biomarker for the diagnosis of MAP.(AU)