Genetics of breast cancer among moroccan women: a literature review

Introduction: Breast cancer (BC) is a heterogeneous disease defined by the accumulation of various molecular alterations that accord each tumor a specific phenotype. Our study aimed to summarize all studies conducted on genetic alterations associated with BC in Moroccan women. Methods: We systematically searched literature databases from the time of inception until 31 August 2021 to collect information concerning the mutation spectrum for BC in Morocco. Results: We identified twenty-three studies including 1858 cases. According to our literature search, twenty-nine mutations were detected in 92/468 (19.66%) patients for BRCA1/BRCA2 genes. We captured eighteen mutations dispersed in the exons 2, 3, 5, 11, 16, 17, 18, and 20 of the BRCA1 gene (c.68_69delAG, c.116G>A, c.181T>G, c.798_799delTT, c.3279delC, c.2805delA, c.1016dupA, c.2126insA, c.3453delT, c.2884C>T, c.2596C>T, c.2612C>T, c.1186A>G, c. 1100A>G, c.4942A>T, c.5062-5064delGTT, c.5095C>T and c.5309G>T). Moreover, eleven mutations dispersed in the exons 3, 10, 11, and 14 and intron 6 of the BRCA2 gene were detected (c.289G> T, c.1310_1313delAAGA, c. 3381delT, c.5073dupA, c.5116_5119delAATA, c.6322C>T, c.3847_3848delGT, c.5576-5579delTTAA, c.7110delA, c.7235inG and c.517-1G>A). A few case-control studies have focused on the association of polymorphisms (SNPs) with the genetic susceptibility of developing BC in Moroccan cases in other genes. A significant association between MTHFR 677T allele (OR: 2.49, 95% CI: 1.17-5.29, p = 0.017), TP53 72Pro variant (OR 2.2, 95% CI 1.07-4.54, p = 0.03), CYP2D6*3variant (OR=2.08, CI 1.28-3.39, p=0.003) and the risk of developing BC was observed. Additionally, the rs1799793 ERCC2 polymorphism, four SNPs in APOBEC3B, and one SNP in APOBEC3A were significantly associated with BC risk (p <= 0.05). Conclusion: This review will allow updating the Moroccan Human Mutation Database. However, large studies including more mutations and polymorphisms are required to determine the prevalence of these mutations in the Moroccan population. This could be very beneficial to guide specific and more effective therapeutic strategies in our country.