title: Tumor necrosis factor-alpha gene polymorphisms in relation to periodontitis.
abstract: BACKGROUND
  Genetic polymorphisms for cytokines have been proposed as potential genetic markers for destructive periodontal disease. The present aim was to investigate 4 bi-allelic polymorphisms in the TNF-alpha gene in relation to susceptibility for and severity of periodontitis. The polymorphisms were all transitions from G to A, 3 in the promoter positions: -376, -308, -238; and one in the first intron at position +489.
  
  
  METHODS
  90 periodontitis patients and 264 reference control subjects were genotyped and frequencies of genotypes and alleles were analyzed. Also genotype frequencies among severe and moderate periodontitis patients were explored, and the % of teeth with 50% bone loss and the % of teeth without any bone loss for patients with the A allele (A+ genotype) and patients without (A- genotype) were compared.
  
  
  RESULTS
  The distributions of genotypes and frequencies of A allele carriage rates for the 4 TNF-alpha polymorphisms were not different between patients and reference controls; Hardy-Weinberg equilibrium criteria were fulfilled. Also the distribution of A+ and A- genotypes, alone or in combinations, were not different for severe periodontitis compared to moderate periodontitis patients. None of the A+ genotypes showed a significant different bone loss pattern compared to A- genotype patients. Smoking status of the patients did not influence the results.
  
  
  CONCLUSIONS
  Genetic polymorphisms in the TNF-alpha gene at positions -376, -308, -238 and +489 could not be identified as susceptibility or severity factors in periodontitis, irrespective of the smoking status of the patients.
authors.affiliation: Department of Periodontology, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Craandijk
authors.forename: Michiel V
authors.initials: MV
authors.lastname: van Krugten
authors.forename: Cor L
authors.initials: CL
authors.lastname: Verweij
authors.forename: Ubele
authors.initials: U
authors.lastname: van der Velden
authors.forename: Bruno G
authors.initials: BG
authors.lastname: Loos
mesh_terms: D000328:Adult; D000483:Alleles; D016301:Alveolar Bone Loss / Q000235:genetics; D000704:Analysis of Variance; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005787:Gene Frequency; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010518:Periodontitis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D014409:Tumor Necrosis Factor-alpha