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BackgroundPopulation history can be reflected in group genetic ancestry, where genomic variation captured by the mitochondrial DNA (mtDNA) and non-recombining portion of the Y chromosome (NRY) can separate female- and male-specific admixture processes. Genetic ancestry may influence genetic association studies due to differences in individual admixture within recently admixed populations like African Americans.Principal FindingsWe evaluated the genetic ancestry of Senegalese as well as European Americans and African Americans from Philadelphia. Senegalese mtDNA consisted of ∼12% U haplotypes (U6 and U5b1b haplotypes, common in North Africa) while the NRY haplotypes belonged solely to haplogroup E. In Philadelphia, we observed varying degrees of admixture. While African Americans have 9–10% mtDNAs and ∼31% NRYs of European origin, these results are not mirrored in the mtDNA/NRY pools of European Americans: they have less than 7% mtDNAs and less than 2% NRYs from non-European sources. Additionally, there is <2% Native American contribution to Philadelphian African American ancestry and the admixture from combined mtDNA/NRY estimates is consistent with the admixture derived from autosomal genetic data. To further dissect these estimates, we have analyzed our samples in the context of different demographic groups in the Americas.ConclusionsWe found that sex-biased admixture in African-derived populations is present throughout the Americas, with continual influence of European males, while Native American females contribute mainly to populations of the Caribbean and South America. The high non-European female contribution to the pool of European-derived populations is consistently characteristic of Iberian colonization. These data suggest that genomic data correlate well with historical records of colonization in the Americas.

Objectives: The aim of our study was to investigate the relation of some sociodemographic factors and delays presentation in breast cancer. Patients and method: This was an observational study in Breast Unit of Aristide Le Dantec Teaching Hospital in Dakar. Were included in the study all patients followed for breast cancer from January 2008 to December 2014. The following variables were selected and stratified: age, place of living, educational attainment, menopausal status, socioeconomic status and family history of breast cancer. For each variable, an association with the stage and presentation delay was assessed. Results: Two hundred and fifty nine (259) patients met the inclusion criteria. No correlation was found between the studied socio-demographic factors and delay. Negative history of family breast cancer was associated with presentation delay. The only factor associated with locally advanced breast cancer after adjusting confounding factors was low level of income. Conclusion: A significant percentage of women with breast cancer in Senegal are experiencing presentation delay. Coordinated efforts with public health department are needed to educate the focused groups and mitigate the barriers.

BRCA1 and BRCA2 are the most incriminated genes in inherited breast/ovarian cancers. Several pathogenic variants of these genes conferring genetic predisposition have been described in different populations but rarely in sub-Saharan Africa. The objectives of this study were to identify pathogenic variants of the BRCA genes involved in hereditary breast cancer in Senegal and to search for a founder effect. We recruited after free informed consent, 27 unrelated index cases diagnosed with breast cancer and each having a family history. Mutation screening of the genes identified a duplication of ten nucleotides c.815_824dupAGCCATGTGG, (p. Thr276Alafs) (NM_007294.3) located in exon 11 of BRCA1 gene, in 15 index cases (allelic frequency 27.7%). The pathogenic variant has been previously reported in African Americans as a founder mutation of West African origin. Haplotypes analysis of seven microsatellites surrounding the BRCA1 gene highlights a shared haplotype encompassing~400 kb between D17S855 and D17S1325. This haplotype was not detected in none of 15 healthy controls. Estimation of the age of the pathogenic variant suggested that it occurred~1400 years ago. Our study identified a founder pathogenic variant of BRCA1 predisposing to breast cancer and enabled the establishment of an affordable genetic test as a mean of prevention for Senegalese women at risk.npj Genomic Medicine (2020) 5:8 ; https://doi.

Chronic kidney disease is an emerging public health issue in Africa. At end-stage renal disease (ESRD), patients need hemodialysis (HD), which may expose them to blood transmitted infections, such as the hepatitis C virus (HCV). Sub-Saharan Africa has the highest HCV prevalence in the world, but data on HD patients is scarce and shows an exceptionally high rate in Senegal. To assess the efficacy of preventive measures in reducing HCV infection among dialysis patients, we retrospectively conducted a cross-sectional study in three Senegalese HD centers, including all HD patients who performed HCV serology between 1 st and 31 st August 2011. The demographical, clinical, and biological data were collected for each patient. We included 106 patients with a mean age of 43.4±15.8 years (range from 18 to 80 years), with 52.8% males. HD vintage was 60.5±15 months (range from six to 206 months). The main causes of kidney disease included nephrosclerosis (36%) and diabetes (24%). The prevalence of HCV was 5.6%, with one patient co-infected with the hepatitis B virus. After adjusting for age and sex, HD vintage was the only risk factor for HCV infection, while nutritional status and the number of blood transfusions did not significantly correlate with HCV infection. We conclude that during the past decade, the prevalence of HCV infection in HD patients living in Senegal has declined considerably, mainly because of improved transfusion measures and better clinical practice in the HD centers. Such efforts should be maintained and reinforced to reduce the seroprevalence of HCV infection.