title: Distribution of FcgammaRIIa and FcgammaRIIIb genotypes in patients with generalized aggressive periodontitis.
abstract: BACKGROUND
  Polymorphisms in FcgammaR have been associated with different forms of periodontitis. This study determined the frequency of FcgammaRIIa and FcgammaRIIIb alleles/genotypes in patients with generalized aggressive periodontitis (GAgP).
  
  
  METHODS
  Thirty-one GAgP and 49 periodontally healthy Brazilian subjects participated in the study. Full-mouth periodontal examinations were carried out, and mouthwash samples were collected for human DNA isolation. FcgammaR genotyping was performed by polymerase chain reaction and hybridization with allele-specific oligonucleotide probes. Significant differences between groups were sought by Mann-Whitney, chi2, and Fisher exact tests and configural frequency analysis.
  
  
  RESULTS
  FcgammaRIIa-H131 (53.8%) and FcgammaRIIIb-NA1 (75%) were the most prevalent alleles in this sample population. A significant overrepresentation of FcgammaRIIIb-NA2 was observed in the GAgP group, whereas FcgammaRIIIb-NA1 was detected more often in healthy individuals (odds ratio, 32.5; 95% confidence interval [CI], 10.6 to 99.8; P<0.001). No significant differences in the distribution of the FcgammaRIIa genotypes were observed between the groups. The prevalence of FcgammaRIIIb-NA2/NA2 was higher in GAgP patients, whereas FcgammaRIIIb-NA1/NA1 was predominant in the healthy group (chi2=45.1; P<0.001). The combination of the genotypes FcgammaRIIIb-NA2/NA2 plus FcgammaRIIa-H/H131 was observed more frequently in GAgP subjects than expected from marginal frequencies (chi2=12.5; P<0.001).
  
  
  CONCLUSIONS
  The data suggest that the FcgammaRIIIb-NA2 allele and/or FcgammaRIIIb-NA2/NA2 genotype and the composite genotype FcgammaRIIIb-NA2/NA2 plus FcgammaRIIa-H/H131 may be associated with GAgP, whereas FcgammaRIIIb-NA1 and/or FcgammaRIIIb-NA1/NA1 may be related to periodontal health in this sample of the Brazilian population.
authors.affiliation: Department of Periodontology, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Rodrigo C
authors.initials: RC
authors.lastname: de Souza
authors.forename: Ana Paula V
authors.initials: AP
authors.lastname: Colombo
mesh_terms: D000328:Adult; D000483:Alleles; D015703:Antigens, CD / Q000235:genetics*; D001938:Brazil; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D058851:GPI-Linked Proteins; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D016014:Linear Models; D008297:Male; D016017:Odds Ratio; D010518:Periodontitis / Q000235:genetics* / Q000276:immunology; D011110:Polymorphism, Genetic; D017452:Receptors, IgG / Q000235:genetics*
chemical_list: D015703:Antigens, CD; C428200:FCGR3B protein, human; C080568:Fc gamma receptor IIA; D058851:GPI-Linked Proteins; D017452:Receptors, IgG