title: Allelic frequencies of host genetic variants influencing susceptibility to HIV-1 infection and disease in South African populations.
abstract: OBJECTIVE
  Limited information is available on the prevalence in African populations of host genetic polymorphisms conferring resistance to HIV-1 infection and disease. The objective of this study was to determine the allelic frequencies in South African populations of the chemokine receptor gene variants CCR5delta32, CCR5m303 and CCR2b-641 and the CXCR4 ligand gene variant SDF1-3'A.
  
  
  METHODS
  Cross-sectional study to determine the prevalence of these gene variants in South African subjects of African and European descent.
  
  
  RESULTS
  The CCR5delta32 genetic variant is rare in individuals of African origin, having an allelic frequency of 0.1% (n = 1247) compared with 9.8% (n = 144) in Caucasians. The CCR5m303 mutation was not detected in Africans (n = 687), whereas an allelic frequency of 0.9% (n = 145) was identified in Caucasians. The frequency of CCR2b-641 allele was 13.1% (n = 180) in Africans, which was significantly higher that the 7.2% (n = 146) detected in Caucasians. Finally the allelic frequency of the SDF1-3'A gene variant was only 1.0% (n = 198) in Africans compared with 19.8% (n = 145) in Caucasians.
  
  
  CONCLUSIONS
  These results indicate that genetic polymorphisms conferring resistance to HIV-1 infection are rare in the South African Black population. Except for the CCR2b-641 gene variant, individuals of African origin also had a much lower prevalence of genetic variants associated with prolonged disease progression.
authors.affiliation: SAIMR Virology, Department of Medical Microbiology, University of Cape Town, Observatory, South Africa.
authors.forename: C
authors.initials: C
authors.lastname: Williamson
authors.forename: S A
authors.initials: SA
authors.lastname: Loubser
authors.forename: B
authors.initials: B
authors.lastname: Brice
authors.forename: G
authors.initials: G
authors.lastname: Joubert
authors.forename: T
authors.initials: T
authors.lastname: Smit
authors.forename: R
authors.initials: R
authors.lastname: Thomas
authors.forename: M
authors.initials: M
authors.lastname: Visagie
authors.forename: M
authors.initials: M
authors.lastname: Cooper
authors.forename: E
authors.initials: E
authors.lastname: van der Ryst
mesh_terms: D000483:Alleles; D001483:Base Sequence; D044383:Black People / Q000235:genetics; D017931:DNA Primers; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D015658:HIV Infections / Q000453:epidemiology* / Q000235:genetics*; D015497:HIV-1 / Q000302:isolation & purification; D006801:Humans; D011110:Polymorphism, Genetic; D019713:Receptors, CCR5 / Q000235:genetics; D019718:Receptors, CXCR4 / Q000235:genetics; D013019:South Africa / Q000453:epidemiology; D044465:White People / Q000235:genetics
chemical_list: D017931:DNA Primers; D019713:Receptors, CCR5; D019718:Receptors, CXCR4