Investigation of BRCA2 Gene K3326X Variant in Patients with Breast and Ovarian Cancer by Next-Generation Sequencing Technique

Introduction: The BRCA2 gene is a tumor suppressor gene involved in the repair of double-stranded DNA damage by homologous recombination. Until now, many cancer-related variants of the BRCA2 gene have been reported. There are conflicting publications in studies of the possible effect of the K3326X variant of this gene in cancer. This study investigates the K3326X BRCA2 gene variant and its role in the cancer pathogenesis of Turkish patients diagnosed with breast and ovarian cancer. Materials and methods: In the study, 1957 patients with cancer diagnosis for BRCA1 and BRCA2 genetic analysis and 432 healthy individuals without a history of cancer were included. The K3326X variant was investigated using the next-generation sequencing method from the genomic DNA sample obtained from the individuals. Results: K3326X variant was detected in 54 of 1957 (2.75%) cancer patients. For the non-cancerous group, 11 of 432 (2.5%) patients were carrying the K3326X variant. When both groups were compared in terms of K3326X variant carriage, a statistically significant result could not be obtained for the individuals (p=0.934). Discussion: BRCA2 K3326X variant did not have a significant role in cancer etiopathogenesis. As a result, the variant whose clinical significance is not still been fully understood, was investigated for the first time for Turkish population. Our results suggest that the variant could be a benign variant.