title: Hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) polymorphism is associated with chronic inflammatory periodontitis. A cross-sectional study.
abstract: BACKGROUND
  Chronic periodontitis (CP) and peri-implantitis (PI) are inflammatory diseases that affect supporting tissues of teeth or implants. The involvement of hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) in neuronal excitability, hyperalgesia, allodynia, spontaneous pain, synaptic plasticity, and rebound activity was previously determined. Recently, scientists found that HCN2 plays an important role in chronic inflammatory pain. This study aimed to evaluate the relationship between gene polymorphisms of HCN2 and CP/PI.
  
  
  METHODS
  A total of 74 patients with CP, 37 patients with PI, and 80 healthy controls presenting to the Periodontology Department of Shahid Beheshti University of Medical Sciences were enrolled. DNA was extracted from fresh blood samples of the arm vein of participants and transferred to KBioscience Institute (UK) for genotyping. χ2-test was performed with SPSS software v.19 for statistical analyses. A p value <0.05 was considered significant.
  
  
  RESULTS
  Both rs55687900 and rs148730222 had significant differences in genotype frequencies between CP and healthy groups (p=0.005 and 0.006, respectively). The allele frequencies also revealed significant frequencies (p=0.004 and 0.006, respectively). The comparison of genotype and allele frequencies between PI and healthy groups had no significant difference.
  
  
  CONCLUSIONS
  HCN2 polymorphism may play a role in CP but not in PI. Despite this approval, more studies with larger sample sizes in different populations are necessary.
authors.forename: Ahmad Reza
authors.initials: AR
authors.lastname: Ebadian
authors.forename: Mahdi
authors.initials: M
authors.lastname: Kadkhodazadeh
authors.forename: Negar
authors.initials: N
authors.lastname: Soltanian
authors.forename: Reza
authors.initials: R
authors.lastname: Amid
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000235:genetics*; D003430:Cross-Sectional Studies; D015921:Dental Implants; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / Q000235:genetics*; D007492:Iran; D008297:Male; D008875:Middle Aged; D057873:Peri-Implantitis / Q000235:genetics*; D011110:Polymorphism, Genetic; D015221:Potassium Channels / Q000235:genetics*; D013280:Stomatitis / Q000235:genetics*
chemical_list: D015921:Dental Implants; C578710:HCN2 protein, human; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D015221:Potassium Channels