title: Genetic diversity and linkage disequilibrium in the chemokine receptor CCR2-CCR5 region among individuals and populations.
abstract: BACKGROUND
  Chemokine receptors CCR2 and CCR5 play a key role in immune and inflammatory responses and have been associated with several diseases, including AIDS. In order to comprehend health disparities it is important to understand the nature of genetic variation in specific genes of interest in different populations. Current studies of the CCR2 and CCR5 receptor genes are primarily focused on the CCR5-Δ32, and CCR2-V64I SNPs.
  
  
  METHODS
  Sanger sequencing was used to sequence the regions containing 16 SNPs in the adjacent CCR2 and CCR5 genes (including CCR5-Δ32, and CCR2-V64I) in 249 subjects of African, European and Hispanic ancestry. Linkage disequilibrium (LD) and haplotypes were determined using Haploview.
  
  
  RESULTS
  The data revealed large differences in allele frequencies of several SNPs and LD patterns among the ethnic groups, including SNPs that were restricted to Africans or Europeans. Seven known CCR5 haplotypes and six novel CCR2 haplotypes were identified. A rare case of an HIV+ subject with the CCR5-Δ32/Δ32 was identified.
  
  
  CONCLUSIONS
  These data demonstrate a LD between CCR2 and CCR5 at several loci and provide new information about CCR2 that contributes to our understanding of its population-specific genetic variability. The data indicate that in addition to CCR5-Δ32 and CCR2-V64I, other SNPs and haplotypes may be important genetic determinants of disease and should be investigated.
authors.affiliation: Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA. Electronic address: clawhorn@rockefeller.edu.
authors.forename: Collene
authors.initials: C
authors.lastname: Lawhorn
authors.forename: Vadim
authors.initials: V
authors.lastname: Yuferov
authors.forename: Matthew
authors.initials: M
authors.lastname: Randesi
authors.forename: Ann
authors.initials: A
authors.lastname: Ho
authors.forename: Susan
authors.initials: S
authors.lastname: Morgello
authors.forename: Mary Jeanne
authors.initials: MJ
authors.lastname: Kreek
authors.forename: Orna
authors.initials: O
authors.lastname: Levran
mesh_terms: D000328:Adult; D005006:Ethnicity / Q000235:genetics; D005787:Gene Frequency / Q000235:genetics; D014644:Genetic Variation; D005828:Genetics, Population; D015894:Genome, Human / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D008297:Male; D054390:Receptors, CCR2 / Q000235:genetics*; D019713:Receptors, CCR5 / Q000235:genetics*
chemical_list: C515334:CCR2 protein, human; C584933:CCR5 protein, human; D054390:Receptors, CCR2; D019713:Receptors, CCR5
keywords: CCR2; CCR5; Chemokine receptors; Ethnicity; Health disparities