Breast cancer risk associated with BRCA1/2 variants in the Pakistani population.
BACKGROUND
Majority of the BRCA1 and BRCA2 mutations are associated with the risk of sporadic and familial breast cancer. Since these genes are significant in DNA repair mechanisms, we focused homology-directed DNA repair (HDDR) and BRCA complex.


METHODS
We selected BRCA1 variant (rs80356932, 4491C/T) and BRCA2 variant (rs80359182, 319T/C) from the interaction region of BRCA complex and studied in 100 breast cancer patients and 100 controls using tetra-ARMS-PCR.


RESULTS
Here we show that BRCA1 and BRCA2 variants are significantly associated with high breast cancer risk (BRCA1 rs80356932; Genotype T/T OR 8.66, 95% CI 3.16-23.71, p < 0.0001; Allele-T, OR 2.48, 95% CI 1.62-3.81, p < 0.0001 and BRCA2 rs80359182; Genotype C/C OR 4.32, 95% CI 1.95-9.53, p = 0.0001; Allele-C, OR 2.19, 95% CI 1.43-3.34, p = 0.0002). Additionally, bioinformatics analysis showed that BRCA2-tryptophan > arginine substitutions result in altered interaction of BRCA1/PALB2/BRCA2/protein complex and impaired HDDR pathway. We also observed that breast cancer risk was significantly increased in over-weighted and obese women.


CONCLUSIONS
Our results indicate that high risk of breast cancer is significantly associated with BRCA1 and BRCA2 variants, and mutations may alter the protein interactions of BRCA complex that results in tumor genesis.
['Abbas|Saba|S|', 'Siddique|Ayesha|A|', 'Shahid|Naeem|N|', 'Khan|Rabbia Tariq|RT|', 'Fatima|Warda|W|']
D000328:Adult D000368:Aged D019313:BRCA1 Protein D024682:BRCA2 Protein D001943:Breast Neoplasms D000076164:Fanconi Anemia Complementation Group N Protein D005260:Female D056726:Genetic Association Studies D020022:Genetic Predisposition to Disease D005838:Genotype D006801:Humans D008875:Middle Aged D062105:Molecular Docking Simulation D009154:Mutation D010154:Pakistan D020641:Polymorphism, Single Nucleotide
Breast cancer BRCA complex Genetic variants Homologue-directed DNA Repair