title: FCGR3B copy number variation is associated with systemic lupus erythematosus risk in Afro-Caribbeans.
abstract: OBJECTIVE
  To evaluate FCGR3B copy number variation (CNV) in African and European populations and to determine if FCGR3B copy number is associated with SLE and SLE nephritis risk in Afro-Caribbeans, adjusting for African genetic ancestry.
  
  
  METHODS
  We estimated FCGR3B to determine if there were ethnic variations in CNV (unrelated unadmixed Europeans and Africans). We then examined CNV at FCGR3B in relation to SLE and SLE nephritis within a case-control collection of 134 cases of SLE (37 with SLE nephritis) and 589 population controls of mainly Afro-Caribbean descent resident in Trinidad.
  
  
  RESULTS
  We found a significant difference in copy number FCGR3B distribution between unadmixed African and European UK cohorts, with 27 (29%) vs 3 (5%) for those with low (0 or 1) copy FCGR3B, respectively, P = 0.002. In a Trinidadian SLE case-control study, low FCGR3B CNV was associated with SLE risk 1.7 (95% CI 1.1, 2.8), P = 0.02, which remained after adjustment for African genetic ancestry; odds ratios (ORs) 1.7 (95% CI 1.0, 2.8), P = 0.04.
  
  
  CONCLUSIONS
  Our studies suggest that FCGR3B low copy number is associated with SLE risk in Afro-Caribbean populations independently of CNV due to African ancestry.
authors.affiliation: Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK. mariam.molokhia@lshtm.ac.uk
authors.forename: Mariam
authors.initials: M
authors.lastname: Molokhia
authors.forename: Manuela
authors.initials: M
authors.lastname: Fanciulli
authors.forename: Enrico
authors.initials: E
authors.lastname: Petretto
authors.forename: Alan Leslie
authors.initials: AL
authors.lastname: Patrick
authors.forename: Paul
authors.initials: P
authors.lastname: McKeigue
authors.forename: Amy L
authors.initials: AL
authors.lastname: Roberts
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Vyse
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Aitman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044383:Black People / Q000235:genetics*; D017691:Caribbean Region / Q000453:epidemiology; D015331:Cohort Studies; D056915:DNA Copy Number Variations; D005260:Female; D058851:GPI-Linked Proteins / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D015994:Incidence; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000208:ethnology* / Q000235:genetics*; D008181:Lupus Nephritis / Q000208:ethnology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D017452:Receptors, IgG / Q000235:genetics*; D012016:Reference Values; D018570:Risk Assessment; D044465:White People / Q000235:genetics; D055815:Young Adult
chemical_list: C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; D017452:Receptors, IgG