title: Variability at the FCGR locus: characterization in Black South Africans and evidence for ethnic variation in and out of Africa.
abstract: This study set out to comprehensively investigate all known functional FcγR variants in South African Black and Caucasian individuals. Population diversity was further assessed using data from the 1000 Genomes Project. In our cohort, Black South Africans neither possessed the haplotypes previously associated with increased surface densities of FcγRIIb and FcγRIIIa nor the FCGR2C haplotype recently associated with increased vaccine efficacy in the RV144 HIV-1 vaccine trial (despite 48.7% bearing the c.134-96T tag allele). Moreover, Africans (South Africans, Luhya Kenyans and Yoruba Nigerians) lack the FCGR2C c.798+1G splice-site allele required for the expression of functional FcγRIIc. Although the presence or absence of surface FcγRIIc did not affect natural killer cell-mediated antibody-dependent cellular cytotoxicity capability, this may be significant for other FcγRIIc-mediated functions. Overall, allele distribution and linkage disequilibrium in Africans and Caucasians differed in a manner that would suggest a differentially maintained balance of FcγR-mediated cell activation in these populations. Finally, significant variation observed among different African populations precludes the use of any one African population as a proxy for FcγR diversity in Africans. In conclusion, the findings of this study highlight further ethnic variation at the FCGR gene locus, in particular for FCGR2C, a gene with increasingly recognized clinical significance.
authors.affiliation: Centre for HIV and STIs, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa.|Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Lassaunière
authors.affiliation: Centre for HIV and STIs, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa.|Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: C T
authors.initials: CT
authors.lastname: Tiemessen
mesh_terms: D016915:AIDS Vaccines / Q000627:therapeutic use; D000353:Africa, Southern; D000483:Alleles; D044383:Black People; D015870:Gene Expression; D005787:Gene Frequency; D056426:Genetic Loci; D015658:HIV Infections / Q000208:ethnology* / Q000235:genetics* / Q000276:immunology / Q000517:prevention & control; D015497:HIV-1 / Q000502:physiology; D006239:Haplotypes; D016045:Human Genome Project; D006801:Humans; D015810:Linkage Disequilibrium; D008875:Middle Aged; D011110:Polymorphism, Genetic; D017452:Receptors, IgG / Q000235:genetics* / Q000276:immunology; D044465:White People
chemical_list: D016915:AIDS Vaccines; C445323:FCGR2A protein, human; C499173:FCGR2B protein, human; C000609718:FCGR2C protein, human; D017452:Receptors, IgG