Background and study aim Carrying a pathogenic BRCA1/2 variant increases greatly young women’s risk of developing breast cancer (BC). This study aimed to provide the first genetic data on BC in Mauritania. Methods Using NGS based screening; we searched for BRCA1/2 variants in DNA samples from 137 patients diagnosed for hereditary BC. Results We identified 16 pathogenic or likely pathogenic (PV) variants carried by 38 patients. Two predominant BRCA1 PV variants were found: c.815_824dup and c.4986 + 6 T > C in 13 and 7 patients, respectively. Interestingly, three novels BRCA1/2 predicted pathogenic variants have also been detected. Notably, no specific distribution of BRCA1/2 variants was observed regarding triple negative breast cancer (TNBC) or patient gender status. Conclusions In this first genetic profiling of BC in Mauritania, we identified a substantial number of BRCA1/2 pathogenic variants. This finding could be important in the future diagnosis and prevention policy of hereditary BC in Mauritania.

Although recessive mutations in GJB2 are the common genetic etiology of sensorineural hearing impairment (SNHI), variants in LRTOMT gene were also identified, mostly in Middle East and North African populations. Methods: Using Sanger sequencing we screened the exon 7 of LRTOMT in a cohort of 128 unrelated Mauritanian children with congenital deafness. Results: One biallelic missense mutation, predicted as pathogenic (c.179T>C;p.Leu60Pro) was found at homozygous state in four independent families. This variant, not reported before, was predicted to have a deleterious effect by SIFT (score: 0.01) and a disease-causing effect by Mutation Taster (prob: 1). Exploration of the encoded protein 3D structure revealed a disruption of an organized α helix (in the normal protein structure) to a random conformation. Early fitting of a cochlear implant seemed to improve the auditory ability of the patient carrying the biallelic variant. Conclusion: Further screening using a panel of deafness genes should provide a more comprehensive view of the heterogeneity of deafness genes underlying hearing impairment in our population.

Background Breast cancer is the leading cause of death in African women. The aim of this retrospective study was to assess the incidence, clinico-pathological characteristics, risk factors and outcome of breast cancer in Mauritania.Methods Demographic and clinico‑pathological features of breast cancer were gathered from 11174 patient files of all cancer types referred to the Centre National d’Oncologie (CNO) between January 2009 and December 2020.ResultsBreast cancer was the most common type of cancer identified in women (30.7%). The diseaseincidence increased from 69 in 2009 to 209 in 2020 with a mean age of 49 year sat cancer detection. Grade 3 tumor was diagnosed in 31.8% patients. Stage 3 and metastasic stage were found respectively in 44.9 % and 22.6% of screened women. 40.4% of cancer patients with satisfactory immunohistochemical data were triple negative breast cancer (TNBC) but no significant variation was found in these features between TNBC and non TNBC groups. A 3‐year survival rate of 63% was observed.ConclusionsThese results support the already published studies on the likely genetic basis of breast cancer in our population.