title: The investigation of the origin of Southern Tunisians using HLA genes.
abstract: The south of Tunisia is characterized by marked ethnic diversity, highlighted by the coexistence of native Berbers with Blacks, Jews and Arab-speaking populations. Despite this heterogeneity, genetic anthropology studies investigating the origin of current Southern Tunisians were rarely reported. We examined human leukocyte antigen (HLA) class I (A, B) and class II (DRB1, DQB1) gene profiles of 250 unrelated Southern Tunisians, and compared them with those of Arab-speaking communities, along with Mediterranean and sub-Sahara African populations using genetic distances, neighbor-joining dendrograms, correspondence and haplotype analysis. In total, 137 HLA alleles were detected, which comprised 32 HLA-A, 52 HLA-B, 32 DRB1 and 21 DQB1 alleles. The most frequent alleles were HLA-A*02:01(18.02%), HLA-B*50:01 (9.11%), HLA-DRB1*07:01 (22.06%) and HLA-DQB1*02:01 (17.21%). All pairs of HLA loci show significant linkage disequilibrium. The four loci depict negative Fnd(the normalized deviate of the homozygosity) values indicating an overall trend to balancing selection. Southern Tunisians appear to be closely related to others Tunisian populations including Berbers, North Africans and Iberians. On the contrary, Southern Tunisians were distinct from Palestinian, Lebanese and Jordanian Middle Eastern Arab-speaking population, despite the deep Arab incursions and Arabization that affected Southern Tunisia. In addition, Southern Tunisians were distant from many sub-Saharan communities, evidenced by genetic distance analysis. Collectively, this indicates a limited genetic contribution of Arab invasion and Black caravans on the makeup of Southern Tunisian gene pool.
authors.affiliation: Department of Immunogenetics, National Blood Transfusion Center, Tunis, Tunisia.
authors.forename: Abdelhafidh
authors.initials: A
authors.lastname: Hajjej
authors.affiliation: Department of Medical Biochemistry, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain.
authors.forename: Wassim Y
authors.initials: WY
authors.lastname: Almawi
authors.affiliation: Department of Medical Analysis, Regional Hospital of Gabes, Gabes, Tunisia.
authors.forename: Lasmar
authors.initials: L
authors.lastname: Hattab
authors.affiliation: Laboratory of Immunogenetics, Department of Biology, University of Tunis El Manar, Tunis, Tunisia.
authors.forename: Amel
authors.initials: A
authors.lastname: El-Gaaied
authors.affiliation: Department of Immunogenetics, National Blood Transfusion Center, Tunis, Tunisia.
authors.forename: Slama
authors.initials: S
authors.lastname: Hmida
mesh_terms: D000483:Alleles; D002877:Chromosomes, Human / Q000737:chemistry; D005006:Ethnicity / Q000235:genetics*; D005260:Female; D051456:Gene Flow; D018740:Genetic Heterogeneity; D056426:Genetic Loci; D005828:Genetics, Population; D015234:HLA-A Antigens / Q000235:genetics*; D015235:HLA-B Antigens / Q000235:genetics*; D059866:HLA-DQ beta-Chains / Q000235:genetics*; D059811:HLA-DRB1 Chains / Q000235:genetics*; D006239:Haplotypes; D006579:Heterozygote; D006720:Homozygote; D063426:Human Migration; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D010802:Phylogeny; D012641:Selection, Genetic; D014416:Tunisia
chemical_list: D015234:HLA-A Antigens; D015235:HLA-B Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D059811:HLA-DRB1 Chains