Interleukin-6 receptor gene polymorphisms and periodontitis in a non-smoking Japanese population

J Clin Periodontol. 2006 Oct;33(10):704-9. doi: 10.1111/j.1600-051X.2006.00978.x. Epub 2006 Aug 7.


Aim: The indispensable role of interleukin-6 receptor (IL-6R) in regulating IL-6 responses has been clearly established. We have previously reported that IL6R polymorphisms strongly influenced the serum levels of soluble IL-6R. In this study, we investigated the association between these genetic variations and periodontitis.

Material and methods: Among the seven novel IL6R single-nucleotide polymorphisms (SNPs) reported, we genotyped two important sites: the +48892 A/C in exon 9 and the -183 G/A in the promoter region. The SNP in exon 9 results in Asp-->Ala substitution in the proteolytic cleavage site of IL-6Ralpha. In total, 212 periodontitis cases and 210 healthy controls were genotyped using polymerase chain reaction, restriction fragment length polymorphisms and direct sequencing methods.

Results: Analysis of the genotype distribution of the +48892 A/C SNP in periodontitis patients and in controls revealed a suggestive association with aggressive (p = 0.04) and chronic periodontitis (p = 0.04). In addition, the carriage rate for the A allele was significantly higher in chronic periodontitis patients [p = 0.02, odds ratio (OR) = 2.25]. No association was found in the -183 G/A SNP. The two markers were in linkage disequilibrium (LD) (|D'| = 0.53).

Conclusion: The IL6R+48892 A/C polymorphism could act as a risk factor for periodontitis; however, further association and biological studies are needed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine
  • Adult
  • Aged
  • Alanine / genetics
  • Alleles
  • Aspartic Acid / genetics
  • Biomarkers / analysis
  • Cytosine
  • Exons / genetics
  • Female
  • Genetic Variation / genetics
  • Genotype
  • Humans
  • Japan
  • Linkage Disequilibrium / genetics
  • Male
  • Middle Aged
  • Periodontitis / genetics
  • Periodontitis / immunology*
  • Polymorphism, Genetic / genetics*
  • Polymorphism, Single Nucleotide / genetics
  • Promoter Regions, Genetic / genetics
  • Receptors, Interleukin-6 / genetics*


  • Biomarkers
  • Receptors, Interleukin-6
  • Aspartic Acid
  • Cytosine
  • Adenine
  • Alanine