APPLICATION OF THE TARGETED MULTIGENE SEQUENCING FOR THE SEARCH OF HEREDITARY BREAST CANCER MUTATIONS IN RUSSIAN PATIENTS

Understanding of the molecular-genetic pathogenesis of hereditary cancer syndrome is extremely important for developing of personal therapeutic approaches and for improving the effectiveness of preventive measures. Today, the optimal solution for the search of causative germ-line mutations in hereditary breast cancer (BC) patients is the next-generation sequencing-based multigene mutational screening. The authors have assembled a targeted panel of 31 genes, based on their potential involvement in the cancer susceptibility and taking into account the frequency of pathogenic alleles in the Russian population. It includes the “canonical” genes of hereditary breast cancer (BRCA1, BRCA2, BRIP1, PALB2, TP53, ATM, NBN), the recently identified “novel” genes (BLM, FANCD2, POLE, FANCM, RAD51C, MRE11A, RECQL, as well as some other genes involved in DNA repair, apoptosis and genome stability maintenance. 94 patients with hereditary BC of unknown genetic etiology were subjected to targeted sequencing. As a result, causative germ-line mutations were identified in 21/94 (22.3%) patients. Importantly, 19 patients harbored rare non-founder BRCA1 and BRCA2 mutations. In the remaining two cases, the functions of the ATM (p.Glu73fs) and POLE (p.Leu1171fs) genes were disrupted. The obtained data are of evident clinical importance; they argue for the expanding of diagnostic panels for monitoring at-risk individuals and for moving the standards of routine clinical diagnostics towards the targeted next-generation sequencing of multigene panels.