Screening of BRCA1 and BRCA2 germline mutations in unselected triple-negative breast cancer patients: A series from north of Morocco

Background: Triple-negative breast cancer (TNBC) is strongly associated with BRCA1 and BRCA2 germline pathogenic variants. Revised NCCN guidelines recommend that TNBC patients =60 years of age should be referred for genetic counseling and consideration of BRCA1/2 testing. The aim of the present study is to characterize germline BRCA1 and BRCA2 variants in a series of TNBC patients from the north of Morocco. Methods: We analyzed BRCA1 and BRCA2 genes by next generation sequencing in a cohort of 32 patients unselected for family history and age of diagnosis. Results: Among 32 patients with TNBC, 7 carried a pathogenic BRCA1 or BRCA2 variant (21.87%). Six patients carried a pathogenic BRCA1 variant and one carried a pathogenic BRCA2 variant. Overall, six different pathogenic BRCA1 or BRCA2 variants were identified, including frameshift, nonsense, and missense variants. The BRCA1 missense c.5309G>T, a founder pathogenic variant in the Moroccan population, was identified in two unrelated patients. In addition, six variants of unknown clinical significance were identified. Conclusions: The understanding of BRCA1 and BRCA2 status in TNBC patients plays an important role in optimizing the preventive and therapeutic management. Despite the small size of our cohort, we believe that this work would help broaden our knowledge of TNBC and BRCA1/2 variants in Morocco.