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Updated: Feb 10, 2026

Functional Assessment of BRCA1 variants using CRISPR-Mediated Base Editors
Published on: February 28, 2021
Identification of BRCA1 and BRCA2 Germline Mutations in Female Breast Cancer Patients Using Next Generation
Menha Swellam1,2, Mohamed K Khalifa3,4, Amira M Nageeb1,2
1Biochemistry Department, Biotechnology Research Institute, Giza, Egypt.
Background:
Breast cancer is the most common cancer affecting females according to WHO 2020 report, with BRCA1 and BRCA2 identified as the major tumor suppressor genes linked to disease susceptibility. Hence, the purpose of the current study was to investigate germline mutations among these genes in a group of Egyptian female breast cancer patients.
Methods:
Blood samples from primary breast cancer patients (n=22), benign breast lesions (n=5) and healthy controls (n=7) were sequenced for BRCA genes by next generation sequencer.
Results:
A total of 135 genetic variations were detected, 59 in BRCA1 and 76 BRCA2, 2 indels (insertion-deletion) and 133 SNV (single nucleotide variation), nearly 55% of those variants were missense variants, 38% were synonymous and 7% were nonsense. A total of 59 variations were detected in BRCA1 and they were categorized as exonic (n=10) and intronic (n=49) regions, BRCA1 exonic variants were categorized into: missense (n=12), non-coding transcript (n=11) synonymous (n=6), splice region synonymous (n=2), stop gain (n=2) and 3-prime UTR (n=1) variants. Regarding variations detected in BRCA2, 55 intronic and 21 exonic variants were identified. Among these 21 variants; 13 novel mutations and 8 formally reported as follows: 7 as benign and one previously reported with contradictory pathogenicity according to the Clinvar database which is a freely available, public archive of reports of the relationships between human variations and phenotypes hosted by the National Center for Biotechnology Information (NCBI) and funded by intramural National Institutes of Health (NIH) funding.
Conclusion:
BRCA1 and BRCA2 germline profiling based on next-generation sequencing technology among Egyptian breast cancer female patients revealed 135 germline variations -104 intronic and 31 exonic, respectively. Among the exonic variants; 13 were newly reported mutations. Hence further study is required to enhance mutational analysis which may benefit clinical system.
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