Investigation of Hereditary Cancer Predisposition Genes of Patients with Colorectal Cancer: Single-centre Experience.

OBJECTIVE: To investigate the genetic causes of colorectal cancers (CRCs); and to determine the genotype-phenotype correlation. STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Department of Medical Genetics, Diskapi Yildirim Beyazit Training and Research, Hospital, Ankara, Turkey, between January 2018 and January 2020. METHODOLOGY: 59 cancer susceptibility genes of 41 patients, included in the study and diagnosed with CRC, were examined using next generation sequencing (NGS) technique. Statistical analysis of the possible relationships among the mutation carrier status of the patients and the parameters of gender, age at diagnosis, and family cancer history, were performed. RESULTS: The mean age at diagnosis of all CRC patients was 48.7 years (range 28-74). Mutations in MLH1, MSH6, CHEK2, PMS2 and MUTYH genes were detected in 10 patients (24.4%). The mean age at diagnosis of CRC was 46.2 years in those who carried the mutation, while it was 49.5 years in those without. Carriers and non-mutation carriers, when compared in terms of age at diagnosis, gender, family cancer history, no significant difference was observed. CONCLUSION: Genes that may cause susceptibility to cancer may play a role in the etiopathogenesis of the CRC. NGS-based multigene panels allow these genes to be detected in the patient and to identify an inherited cancer syndrome. Key Words: Colorectal cancer, Lynch syndrome, Hereditary cancer, Gene, Next generation sequencing.