title: Genetic diversity and prevalence of CCR2-CCR5 gene polymorphisms in the Omani population.
abstract: Polymorphisms in the regulatory region of the CCR5 gene affect protein expression and modulate the progress of HIV-1 disease. Because of this prominent role, variations in this gene have been under differential pressure and their frequencies vary among human populations. The CCR2V64I mutation is tightly linked to certain polymorphisms in the CCR5 gene. The current Omani population is genetically diverse, a reflection of their history as traders who ruled extensive regions around the Indian Ocean. In this study, we examined the CCR2-CCR5 haplotypes in Omanis and compared the patterns of genetic diversity with those of other populations. Blood samples were collected from 115 Omani adults and genomic DNA was screened to identify the polymorphic sites in the CCR5 gene and the CCR2V64I mutation. Four minor alleles were common: CCR5-2554T and CCR5-2086G showed frequencies of 49% and 46%, respectively, whereas CCR5-2459A and CCR5-2135C both had a frequency of 36%. These alleles showed moderate levels of heterozygosity, indicating that they were under balancing selection. However, the well-known allele CCR5Δ32 was relatively rare. Eleven haplotypes were identified, four of which were common: HHC (46%), HHE (20%), HHA (14%) and HHF*2 (12%).
authors.affiliation: Division of Immunology, Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman .
authors.forename: Samira H
authors.initials: SH
authors.lastname: Al-Mahruqi
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman .
authors.forename: Fahad
authors.initials: F
authors.lastname: Zadjali
authors.affiliation: Center for Research in Biodiversity and Genetic Resources & Department of Biology, Faculty of Sciences, Universidade do Porto, Portugal .
authors.forename: Albano
authors.initials: A
authors.lastname: Beja-Pereira
authors.affiliation: Division of Immunology, Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman .
authors.forename: Crystal Y
authors.initials: CY
authors.lastname: Koh
authors.affiliation: Infectious Diseases Unit, Department of Medicine, Sultan Qaboos University Hospital, Muscat, Oman .
authors.forename: Abdullah
authors.initials: A
authors.lastname: Balkhair
authors.affiliation: Division of Immunology, Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman .
authors.forename: Ali A
authors.initials: AA
authors.lastname: Al-Jabri
keywords: CCR2; CCR5; HIV-1; Oman; divergence; haplotype