title: Identification of the CCR5-Delta32 HIV resistance allele and new mutations of the CCR5 gene in different Tunisian populations.
abstract: Polymorphisms in some chemokine receptor genes are associated with susceptibility to and progression of human immunodeficiency virus-1 (HIV-1) infection. Most mutations detected in the CC-chemokine receptor 5 (CCR5) gene are specific to different populations. In this study, we focused on polymorphisms of the CCR5 coding region in three healthy populations from Tunisia, corresponding to a cosmopolitan population from Tunis, and two isolated Berber populations. In addition to the CCR5-Delta32 deletion, eleven single nucleotide polymorphisms were detected. Some of these point mutations were associated with the same genotype and even the same haplotype. The (L55Q-C101X), I124, V131F, T143N, A159V, I237, T239A and G301R alleles have not been described previously, whereas the CCR5-Delta32, L55Q, A335V and Y339F variants have already been reported in the literature. The distribution and frequency of these variants were different among the three groups studied, a result in agreement with the mosaic genetic structure of the Tunisian population. To determine whether these alleles affect HIV-1 transmission, we compared allele frequencies between healthy and HIV-1 infected individuals from Tunis. The frequency of the CCR5-Delta32 variant was significantly different between the two groups, leading us to conclude that this mutation might confer protection against HIV infection in Tunisian populations.
authors.affiliation: Laboratoire de Génétique, Immunologie et Pathologies Humaines, Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis, Tunisie.
authors.forename: Asma
authors.initials: A
authors.lastname: Jlizi
authors.forename: Joanne
authors.initials: J
authors.lastname: Edouard
authors.forename: Karima
authors.initials: K
authors.lastname: Fadhlaoui-Zid
authors.forename: Sabah
authors.initials: S
authors.lastname: Frigi
authors.forename: Patrice
authors.initials: P
authors.lastname: Debré
authors.forename: Amine
authors.initials: A
authors.lastname: Slim
authors.forename: Ioannis
authors.initials: I
authors.lastname: Theodorou
authors.forename: Amel Ben Ammar
authors.initials: AB
authors.lastname: El Gaaied
authors.forename: Wassila
authors.initials: W
authors.lastname: Carpentier
mesh_terms: D000328:Adult; D000483:Alleles; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D015658:HIV Infections / Q000235:genetics* / Q000276:immunology / Q000635:transmission / Q000821:virology; D015497:HIV-1; D006239:Haplotypes; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D008297:Male; D009154:Mutation; D011110:Polymorphism, Genetic; D019713:Receptors, CCR5 / Q000235:genetics*; D014416:Tunisia
chemical_list: D019713:Receptors, CCR5