Screening of BRCA1 (c.5177_5180delGAAA rs80357867 and c.4986+6T>C rs80358086) and the BRCA2 (c.6445_6446delAT rs80359592) Genes for Breast Cancer Prevention in Burkina Faso.

Background: The objective of this study is to search for mutations in the BRCA1 (c.5177_5180delGAAA and c.4986+6T>C) and BRCA2 genes (c.6445_6446delAT) in a population of women diagnosed with breast cancer. Methods: This is a case-control study that involved 140 participants, including 70 patients with histologically diagnosed breast cancer and 70 healthy women without breast cancer. Mutations in the BRCA1 (rs80357867, rs80358086) and BRCA2 (rs80359592) genes were tested by real-time PCR. The 95% confidence interval Odds Ratio (OR) was used to estimate the associations between specific genotypes and breast cancer. Results: The study revealed that no mutations were detected for rs80359592. Similarly, no reference allele (TTTC/TTTC) of rs80357867 was found in this study. However, the homozygous double mutant (-/) genotype of this rs80357867 was observed in 11.43% and 1.43% of patients and controls respectively, while 88.57% of patients and 98.57% of controls had a heterozygous deletion (TTTC/-). Concerning rs80358086, 8.57% of the patients had a heterozygous mutation (A/G) with no significantly risk association with occurrence of breast cancer (OR = 6.46; 95% CI: 0.75-55.21; p = 0.11). In addition, this heterozygous mutation was significantly associated with a family history of breast cancer (OR=128; 95% CI: 9.46-1730.93) and breast cancer risk in nonmultiparous women (OR=6; 95% CI: 1-35.90; p= 0.05) but no association with overweight/obesity (OR=1.66; 95% CI: 0.18-15.35; p=1). Conclusion: This study shows high frequencies of heterozygous mutation of rs80357867 and rs80358086 from patients. In Burkina Faso, these results could help with early diagnosis of breast cancer in patients.

Mutations in exon 11 (11.1 and 11.2) of the BRCA1 gene and risk factors for breast cancer in Burkina Faso.

Breast cancer is the leading cause of death among women in both developed and developing countries. It is multifactorial, including genetic predispositions such as oncogenic mutations on BRCA1 and 2 genes. The objectives of the present study were to identify oncogenic mutations in exon 11 of the BRCA1 gene and to determine the risk factors for breast cancer among women population in Burkina Faso. This study involved 100 women, including 50 cases of breast cancer and 50 controls (no clinical signs and no family history of breast cancer or other cancers). Mutations in the BRCA1 gene were detected by PCR using sequence primers specific for exon 11 fragments (11.1 and 11.2). In our study population, age (OR=22.40; CI: 4.33-115.82; p<0.001) and obesity (OR=4.23; CI: 1.64-10.92; p=0.003) were risk factors while multiparity was a protective factor for breast cancer (OR=0.35; CI: 0.15-0.81; p=0.02). A mutation was found on both fragments 11.1 and 11.2 of the BRCA1 gene exon 11 in 04/50 (8.0 %) of patients. No mutations were observed in controls. The present study revealed high frequency of oncogenic mutations in exon 11 fragments (11.1 and 11.2) of the BRCA1 gene. These mutations on exon 11 are and involved in the occurrence of breast cancer in our population. Age and obesity were also risk factors for breast cancer among women population in Burkina Faso.