336P - Determination of the most common hereditary mutations associated with breast cancer and ovarian cancer in the population of Ukrainian women

Background

The population of Ukraine was formed as a result of several millennia of migration and medley of races. This, in turn, formed a great genetic diversity of the population living in Ukraine today. The objective of our research is to study the most common hereditary genetic disorders associated with the syndrome of familial breast cancer (hereinafter referred to as BC) and ovarian cancer (hereinafter referred to as OC) in the population of Ukrainian women.

Methods

All studies were carried out by the next-generation sequencing method (hereinafter - NGS) on the Thermo Fisher Ion Torrent Proton sequencer. For libraries preparation, Thermo Fisher Ion Chef and CleanPlex® Hereditary Cancer Panel v2 reagents were used.

Results

In order to achieve the objective, for the first time a large-scale study was conducted for the population of women in Ukraine the cohort of which included more than 1,032 patients from different regions of the country who had indications for genetic testing (BC and/or OC and/or positive family history). Blood and/or saliva were taken as biological material. In the course of the study, we identified 213 Pathogenic / Likely pathogenic variants (PV/LPV) (single nucleotide polymorphisms (SNP), deletions, duplications) in 205 samples. In percentage terms, samples with PV/LPV make up 19.9% of the total number of performed studies. Most PV/LPV were identified in the BRCA1 gene where the c.5266dup (p.Gln1756fs) variant was dominant. The second most frequently identified PV/LPV is in the CHEK2 gene where the dominant variant is c.470T>C (p.Ile157Thr). The third gene in terms of the number of PV/LPV found is BRCA2, with the predominant variant being c.475+1G>T. Genetic defects were also found in the following genes: BARD1, PALB2, TP53, ATM, NBN, BLM, MRE11, MSH2 and XRCC2.

Conclusions

Our results of the assessment of genetic disorders in BRCA1 and BRCA2 genes are quite foreseeable for the population of patients with a personal and/or family history of breast or ovarian cancer. However, it should be noted that the frequency of mutations in the CHEK2 gene is quite high and the frequency of mutations in the PALB2 gene is relatively low compared to studies in other populations in the world.

Clinical trial identification

Editorial acknowledgement

We would like to thank LifeCode Laboratories for the information provided and the opportunity to conduct the study.

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.