title: The genetics of East African populations: a Nilo-Saharan component in the African genetic landscape.
abstract: East Africa is a strategic region to study human genetic diversity due to the presence of ethnically, linguistically, and geographically diverse populations. Here, we provide new insight into the genetic history of populations living in the Sudanese region of East Africa by analysing nine ethnic groups belonging to three African linguistic families: Niger-Kordofanian, Nilo-Saharan and Afro-Asiatic. A total of 500 individuals were genotyped for 200,000 single-nucleotide polymorphisms. Principal component analysis, clustering analysis using ADMIXTURE, FST statistics, and the three-population test were used to investigate the underlying genetic structure and ancestry of the different ethno-linguistic groups. Our analyses revealed a genetic component for Sudanese Nilo-Saharan speaking groups (Darfurians and part of Nuba populations) related to Nilotes of South Sudan, but not to other Sudanese populations or other sub-Saharan populations. Populations inhabiting the North of the region showed close genetic affinities with North Africa, with a component that could be remnant of North Africans before the migrations of Arabs from Arabia. In addition, we found very low genetic distances between populations in genes important for anti-malarial and anti-bacterial host defence, suggesting similar selective pressures on these genes and stressing the importance of considering functional pathways to understand the evolutionary history of populations.
authors.affiliation: Institut de Biologia Evolutiva (UPF-CSIC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Dobon
authors.affiliation: 1] College of Medical Laboratory Sciences, University of Science and Technology, Omdurman, Sudan [2] Banoon ART and Cytogenetics Centre, Bahrain Defence Force Hospital, Manama, Kingdom of Bahrain.
authors.forename: Hisham Y
authors.initials: HY
authors.lastname: Hassan
authors.affiliation: 1] Institut de Biologia Evolutiva (UPF-CSIC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain [2] Departament de Genètica i de Microbiologia, Grup de Biologia Evolutiva (GBE), Universitat Autonòma de Barcelona, Bellaterra (Barcelona), Spain.
authors.forename: Hafid
authors.initials: H
authors.lastname: Laayouni
authors.affiliation: Institut de Biologia Evolutiva (UPF-CSIC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain.
authors.forename: Pierre
authors.initials: P
authors.lastname: Luisi
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands.
authors.forename: Isis
authors.initials: I
authors.lastname: Ricaño-Ponce
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Zhernakova
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, The Netherlands.
authors.forename: Cisca
authors.initials: C
authors.lastname: Wijmenga
authors.affiliation: Sudan Medical and Scientific Research Institute, University of Medical Sciences and Technology, Khartoum, Sudan.
authors.forename: Hanan
authors.initials: H
authors.lastname: Tahir
authors.affiliation: Institut de Biologia Evolutiva (UPF-CSIC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Comas
authors.affiliation: 1] Department of Internal Medicine and [2] Radboud Center for Infectious Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: Mihai G
authors.initials: MG
authors.lastname: Netea
authors.affiliation: Institut de Biologia Evolutiva (UPF-CSIC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Catalonia, Spain.
authors.forename: Jaume
authors.initials: J
authors.lastname: Bertranpetit
mesh_terms: D000351:Africa, Eastern; D044383:Black People / Q000235:genetics*; D016000:Cluster Analysis; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D025341:Principal Component Analysis