title: Analysis of single nucleotide polymorphisms in the 5'-flanking region of tumor necrosis factor-alpha gene in Japanese patients with early-onset periodontitis.
abstract: BACKGROUND
  Early-onset periodontitis (EOP) is considered to have a genetic basis, which has not been clearly defined. The tumor necrosis factor-alpha (TNF-alpha) gene polymorphism as one of the genetic factors may influence the expression of several chronic inflammatory diseases. The aim of the present study was to evaluate whether the polymorphisms in the 5'-flanking region of the TNF-alpha gene are associated with Japanese EOP patients.
  
  
  METHODS
  Forty-six Japanese, generalized EOP (G-EOP) patients and 104 Japanese healthy subjects were identified according to established clinical criteria. Twenty healthy subjects were analyzed by nucleotide sequence to screen polymorphisms of the 5'-flanking region of the TNF-alpha gene. Then, all subjects were analyzed by polymerase chain reaction and sequence-specific oligonucleotide probe (SSOP) methods.
  
  
  RESULTS
  We determined 5 single nucleotide polymorphisms at positions -1031 (T/C), -863 (C/A), -857 (C/T), -308 (G/A), and -238 (G/A) in the 5'-flanking region of the TNF-alpha gene. There were no significant differences in the genotype and allele frequency when we compared G-EOP patients to healthy subjects. Because the frequency of polymorphic alleles at positions -308 and -238 was very low in this study population, we demonstrated the existence of 4 detected haplotypes and 6 detected genotypes concerning 3 single nucleotide polymorphisms (-1031, -863, and -857). The frequency of the H1/H3 (TCC/TCT)-detected genotype tended to decrease in G-EOP patients compared to healthy subjects, but was not statistically significant.
  
  
  CONCLUSIONS
  These findings suggest there is no significant association between polymorphisms in the 5'-flanking region of the TNF-alpha gene and susceptibility to G-EOP in Japanese patients.
authors.affiliation: Department of Periodontology, Faculty of Dentistry, Niigata University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Endo
authors.forename: H
authors.initials: H
authors.lastname: Tai
authors.forename: K
authors.initials: K
authors.lastname: Tabeta
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Yamazaki
authors.forename: H
authors.initials: H
authors.lastname: Yoshie
mesh_terms: D024506:5' Flanking Region / Q000235:genetics*; D000328:Adult; D010520:Aggressive Periodontitis / Q000235:genetics*; D000483:Alleles; D001483:Base Sequence / Q000235:genetics; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D005787:Gene Frequency / Q000235:genetics; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007564:Japan; D008297:Male; D009010:Monte Carlo Method; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D013223:Statistics as Topic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D015345:Oligonucleotide Probes; D014409:Tumor Necrosis Factor-alpha