Screening of germline mutations in young Rwandan patients with breast cancers

Abstract

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Breast cancer in East Africa: Prevalence and spectrum of germline SNV/indel and CNVs in BRCA1 and BRCA2 genes among breast cancer patients in Tanzania

“…Despite the fact that our cohort was not selected for age at diagnosis, the prevalence of germline BRCA1/2 pathogenic variants observed does not differ significantly from that observed in the Rwandan BC patients diagnosed with the disease before 35 years. 12 Our findings also agree with other scholars' findings from unselected Chinese BC patients, 30 Sweden, 31 and Bahrain that analyzed 25 patients selected for early onset of the disease and family history of cancer. 32 However, the prevalence observed in our cohort (6%) is lower compared to that reported in Uganda and Cameroon combined, 33 Morocco, 34 and Mexico.…”

“…This enables simultaneous detection of both variants using a single platform and workflow, which provides high accuracy and shorter turnaround time. 12 , 13 Although the CNVs are seldom reported, they contribute a substantial fraction of germline pathogenic BRCA1/2 variants of about 4%–28%. The CNVs are more common in BRCA1 than in BRCA2 due to the presence of high densities of Alu sequences and homologous recombination events between BRCA1 and its pseudogenes.…”

Absence of Germline BRCA1 c.68_69delAG and c.5266dupC Mutations among Hormone Receptor-negative Breast Cancer Patients: A First Impression at a Tertiary Cancer-care Facility in Tanzania

“…In the current series, Invasive ductal carcinoma of no specific type (IDC-NST) was the most prevalent (86.4%) histological type of breast tumors. These results relate with previous Tanzanian studies (Burson et al 2010, Mwakigonja et al 2017, Mansouri et al 2019 and other East African studies (Galukande et al 2014, Uyisenga et al 2020.…”

“…A limitation of this study is that it focused on investigating the contribution of only germline BRCA1 c.68_69delAG and the c.5266dupC mutations to BC incidence among indigenous BC patients in Tanzania. The targeted Sanger sequencing approach used precluded the ability to detect other germline mutations in other exons of BRCA1 and in other BC susceptibility genes such as BRCA2, CHEK2, and TP53 which are reported to play significant roles in BC predisposition in indigenous Africans (Uyisenga et al 2020). The cross-sectional nature of study and the relatively small sample size of 81 BC patients calls for a larger cohort studies in the future.…”

“…According to studies in Caucasians and Arabs, BC patients harboring either of the c.68_69delAG, the c.5266dupC, or other germline BRCA1 deleterious mutations are associated with early-onset of the disease, high-grade tumors, estrogen and progesterone hormone receptorsnegative subtype (ER-and PR-), and bilaterality (Szwiec et al 2015, Mahfoudh et al 2019. Characterization of germline BRCA1 deleterious mutations is not well established in majority of oncology centers in SSA, despite few studies from South Africa (Francies et al 2015), Rwanda (Uyisenga et al 2020) and Burkina Faso (Zoure et al 2018). Thus, their contribution to alarming BC incidence among indigenous (black) Africans is not clearly known.…”