Abstract
Introduction: Breast cancer (BC) is the most common malignant disease affecting women around the world. Clinically, the most important BC susceptibility genes are BRCA1 and BRCA2. The objective of our study was to establish the frequencies of 8 mutations in the BRCA1 genes (185delAG, 4153delA, 5382insC, 3819delGTAAA, 3875delGTCT, 300T> G (Cys61Gly), 2080delA mutations) and BRCA2 (6174delT mutation) in patients with BC in the Aktobe region of Western Kazakhstan. Materials and research methods: This study involved 300 women with a confirmed diagnosis of BC, who were observed at the Medical Center of the West Kazakhstan Medical University named after Marat Ospanov in the period 2018-2019. Prior to sampling the material (peripheral whole blood), patients received informed consent to conduct the study. Genotyping was carried out by real-time PCR using the Oncogenetics BRCA kit (NPO DNA Technology) according to the manufacturer's instructions. Results: A total of 300 patients were identified 3 cases. Patient No. 1, 31 years old, Asian race (kazakh), a mutation in the BRCA1 5382insC gene was detected, the hereditary history was burdened. Given the patient’s mutation (5382incS), a family history (father died of lung cancer, sibling died of ovarian cancer), work was done on genetic counseling for relatives (mother, brother, sisters and their adult children). Based on the analysis, we revealed a similar mutation of 5382incS in a sibling (42 years old) and his own daughter (17 years old), a second sibling (37 years old). Patient No. 2, 68 years old, Caucasian race, a mutation in the BRCA1 300T> G gene (Cys61Gly) was detected, the hereditary history is not burdened. Patient No. 3, 59 years old, Caucasian race, burdened by heredity. Also, given the patient’s mutation (5382incS), a family history (mother and grandmother died of BC), a study was conducted (daughters). According to the result of the analysis, we revealed a similar mutation of 5382incS in the daughter. Thus, the case presented shows the need for a large-scale, in-depth study of this population for further personification of treatment and prophylactic examination of patient families.