A Study of BRCA1 Gene Exon 2 Mutation in Bangladeshi Female Breast Cancer Patients

Abstract

Background: Breast cancer is the most common malignancy and leading cause of death among women in Bangladesh. Mutations in BRCA genes increase the risk for breast cancer. A large number of distinct mutations and polymorphisms in the BRCA1 gene have been reported worldwide, a frameshift mutation in BRCA1 gene exon 2 (185delAG) is one of the commonly reported mutations. Therefore, the study was planned to determine the frequencies of mutation and polymorphisms in BRCA1 gene exon 2. Materials and Methods: A cross-sectional descriptive type of study was done on 100 adult Bengali Bangladeshi female patients with ductal carcinoma of breast of age range between 25 to 70 years by ‘selection checklist.’ Genomic DNA was isolated from the peripheral blood samples. Amplification of the desired sequence of BRCA1 exon 2 was checked in gel and then digested with restriction endonuclease enzyme (Hinfl). The fragments obtained were analyzed on a gel and photographed under UV light. Sanger sequencing was done on 10 blood samples for confirmation. Sequenced data was analyzed by Geneious Software version 11. Results: The onset of cancer was predominantly below 50 years and 44% of patients did not experience menopause as they developed cancer at a younger age. Gel photographs after enzyme digestion showed wild-type bands of 149bp in all samples. The chromatogram reveals wild-type sequence of exon 2 of BRCA1 gene. Conclusions: BRCA1 mutation status helps us in the cancer risk prediction, selection of therapeutic management and genetic counseling of the patients and families. Therefore, it is necessary to study the whole BRCA1 gene in our population.