Application of a targeted panel to search for genetic variants of hereditary breast cancer

In recent years, genetic testing for the diagnosis of hereditary forms of cancer has increasingly shifted to NGS technologies as a more sensitive and informative method. Objective. To find genetic variants in target regions of genes associated with hereditary types of breast and ovarian cancer by NGS in the biological material of patients with negative results on frequent mutations in the BRCA1/2 genes. Material and methods. The study included DNA samples extracted from tumor tissue and peripheral blood lymphocytes of 21 patient of the Sverdlovsk Regional Oncological Dispensary with breast cancer and negative results of searching pathogenic variants in BRCA1/2 genes by real-time PCR. Sequencing was performed on the MiSeq platform using the Solo-test ABC plus panel. Results. Using targeted NGS sequencing, 13 rare variants were identified in DNA samples from 11 women: seven germline (6 with established pathogenic significance and 1 VUS) and six somatic mutations (4 with activating action and 2 with unclear clinical significance). In four patients, rare BRCA1/BRCA2 mutations not included in the list of common Russian variants were found to be the cause of the disease, four women carried somatic alterations in PIK3CA, ATM and CHEK2, and three others had two variants in their DNA at the same time. Conclusion. The research substantiates the need for introducing multigenic-targeted sequencing into Russian clinical practice of breast cancer research.