title: Association of Toll-like receptor 9 haplotypes with chronic periodontitis in Czech population.
abstract: OBJECTIVE
  Toll-like receptors (TLRs) belong to the pattern recognition receptors family of signal molecules that recognize conserved microbial structures. The aim of this study was to analyse polymorphisms in the TLR genes and their association with chronic periodontitis (CP).
  
  
  METHODS
  Two polymorphisms (2408G/A, i.e. Arg753Gln and -16934A/T) in TLR-2 and three variants (-1486C/T, -1237C/T and+2848A/G) in the TLR-9 genes were studied in 222 patients with CP and 259 unrelated controls. All polymorphisms were detected using the polymerase chain reaction-restriction fragment length polymorphism methods. Subgingival bacterial colonization was investigated by the VariOr Dento test.
  
  
  RESULTS
  No significant differences were found in allele and genotype frequencies of all polymorphisms between patients and controls. Nevertheless, complex analysis revealed differences in TLR9 haplotype frequencies between both groups (p=0.001). Specifically, the haplotype T(-1486)/T(-1237)/A(2848) was significantly more frequent (9.6%versus 2.8%, p<0.000001) and the haplotype T(-1486)/T(-1237)/G (2848) of the TLR9 gene was less frequent (35.9%versus 43.3%, p=0.01) in patients than in controls. However, no significant relationships between periodontal pathogens, TLR polymorphisms and CP were found.
  
  
  CONCLUSIONS
  In conclusion, although no significant role of the TLR2 gene in periodontitis was found, our results indicate that TLR9 haplotypes may be associated with susceptibility to CP.
authors.affiliation: Clinic of Stomatology, Faculty of Medicine, Masaryk University Brno and St. Anne's University Hospital Brno, Brno, Czech Republic. holla@med.muni.cz
authors.forename: Lydie Izakovicova
authors.initials: LI
authors.lastname: Holla
authors.forename: Jan
authors.initials: J
authors.lastname: Vokurka
authors.forename: Barbara
authors.initials: B
authors.lastname: Hrdlickova
authors.forename: Peter
authors.initials: P
authors.lastname: Augustin
authors.forename: Antonin
authors.initials: A
authors.lastname: Fassmann
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001419:Bacteria / Q000145:classification; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D003604:Czechoslovakia; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D010512:Periodontal Index; D020641:Polymorphism, Single Nucleotide; D012016:Reference Values; D051195:Toll-Like Receptor 2 / Q000235:genetics*; D051217:Toll-Like Receptor 9 / Q000235:genetics*; D044465:White People / Q000235:genetics
chemical_list: D051195:Toll-Like Receptor 2; D051217:Toll-Like Receptor 9