In accordance with the Asian BRCA Consortium data, there is a significant difference in incidence rate of breast cancer depending on age, as well as spectrum and prevalence of BRCA1/2 mutations between Mongoloid (East Asian) and Caucasoid (European) people. However, European strategies to identify familial BC are still applied to the Asian population, including Russian Mongoloids (Khakas, Buryats, Tyvans and Yakuts and others). The main purpose of the study was to identify molecular changes associated with hereditary BC in Russian Mongoloid BC patients (Buryats). Thirty-nine patients were included in the study. Genomic DNA extracted from lymphocytes was used to prepare DNA-libraries. Target sequencing was designed to cover 27 genes, such as ATM, APC, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2 and others. Paired-end sequencing (2 × 150 bp) was conducted on a NextSeq 500 system (Illumina, USA). Three pathogenic mutations in non-BRCA genes were found (prevalence of 8%). The pathogenic mutations were found in the RAD51D and PTEN genes. The pathogenic variant in the RAD51D gene (rs137886232, NC_000017.10:g.33428366G>A, p.R141X) was observed in two unrelated individuals aged under 40. One of these patients had a family history of late-onset stomach cancer in second-degree relatives. The pathogenic mutation in the PTEN gene (rs786201044, NC_000010.10:g.89692922T>C, p.C136R) was observed in a 38 years old breast cancer patient with no family history. In our study, we first describe pathogenic mutations in RAD51D and PTEN genes found in young Buryat patients.

根据亚洲BRCA联盟数据，乳腺癌的发病率存在显着差异，取决于年龄，蒙古人（东亚）和高加索人（欧洲）之间BRCA1 / 2突变的谱和患病率。但是，欧洲确定家族性BC的策略仍然适用于亚洲人群，包括俄罗斯人种（Khakas，Buryats，Tyvans和Yakuts等）。这项研究的主要目的是确定俄罗斯蒙古人BC患者（布里亚特人）与遗传BC相关的分子变化。该研究包括三十九名患者。从淋巴细胞提取的基因组DNA用于制备DNA库。靶序列设计涵盖了27个基因，例如ATM，APC，BARD1，BRCA1，BRCA2，BRIP1，CDH1，CHEK2等。配对末端测序（2×150 bp）在NextSeq 500系统（Illumina，美国）上进行。在非BRCA基因中发现了三个致病性突变（发生率8％）。在RAD51D和PTEN基因中发现了致病性突变。在两个40岁以下无关的个体中观察到RAD51D基因的致病变异（rs137886232，NC_000017.10：g.33428366G> A，p.R141X）。其中一名患者第二次有迟发性胃癌家族史度亲戚。PTEN中的致病性突变在没有家族史的38岁乳腺癌患者中观察到该基因（rs786201044，NC_000010.10：g.89692922T> C，p.C136R）。在我们的研究中，我们首先描述了在年轻的布里亚特患者中发现的RAD51D和PTEN基因的致病突变。