Distribution of FcgammaRIIa and FcgammaRIIIb genotypes in patients with generalized aggressive periodontitis.
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.
de Souza
Rodrigo C
RC
Department of Periodontology, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Colombo
Ana Paula V
AP
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*
D015703:Antigens, CD; C428200:FCGR3B protein, human; C080568:Fc gamma receptor IIA; D058851:GPI-Linked Proteins; D017452:Receptors, IgG