title: Association between polymorphism in the promoter region (G/C-915) of PAX9 gene and third molar agenesis.
abstract: OBJECTIVE
  Hypodontia is the congenital absence of one or more (up to six) permanent and/or deciduous teeth, being one of the most common alterations of the human dentition. Genetic polymorphisms are variations of DNA sequences occurring in a population. This study investigated whether G-915C single nucleotide polymorphism (SNPs) in the PAX9 gene promoter is associated with hypodontia in humans.
  
  
  METHODS
  The polymorphism in region G/C-915 of PAX9 gene (NCBI ref SNP ID: rs 2073247) of 240 patients was analyzed, being 110 controls and 130 individuals with third molar agenesis. After DNA extraction, the region of interest was amplified by PCR technique using two different primers. The significance of the differences in observed frequencies of polymorphisms in both groups was assessed by odds-ratio and chi-squared test with 95% confidence interval.
  
  
  RESULTS
  Genotype CC was more frequent in patients with agenesis (11.5%) compared to the control (1.8%), while GG was more prevalent in the control group (39.1%) compared to the individuals with agenesis (26.2%).
  
  
  CONCLUSIONS
  These data showed that the allele C could be associated with the third molar agenesis.
authors.affiliation: Department of Morphology, Dental School of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Fabio José
authors.initials: FJ
authors.lastname: Bianch
authors.forename: Tiago Franco
authors.initials: TF
authors.lastname: de Oliveira
authors.forename: Cristiane Borges Pereira
authors.initials: CB
authors.lastname: Saito
authors.forename: Regina Célia Rocha
authors.initials: RC
authors.lastname: Peres
authors.forename: Sérgio Roberto Peres
authors.initials: SR
authors.lastname: Line