Genes Involved in the Maintenance of Vitamin D Levels Might Be Associated With Mandibular Retrognathism

: In this study we evaluated, if single nucleotide polymorphisms (SNPs) in the genes encoding PTH, VDR, CYP24A1 and CYP27B1 are associated with Mandibular Retrognathism (MR). Samples from biologically-unrelated patients receiving orthodontic treatment were included in this study. Pre-orthodontic lateral cephalograms were used to determine the phenotype. Patients having a retrognathic mandible (SNB<78º) were selected as cases and those with an orthognathic mandible (SNB=78º–82º) were selected as controls. Genomic DNA was used for genotyping analysis of SNPs in PTH (rs694, rs6256 and rs307247), VDR (rs7975232), CYP24A1 (rs464653) and CYP27B1 (rs927650). Chi-squared or Fisher’s tests were used to compare genotype and allele distribution among groups. Haplotype analysis was performed for the SNPs in PTH. The established alpha was p<0.05. Multifactor dimensionality reduction (MDR) was used to identify SNP-SNP interactions. A total of 48 MR and 43 controls were included. In the genotype and allele distribution analysis, the SNPs rs694, rs307247 and rs464653 in were associated with MR (p<0.05). MDR analyses predicted the best interaction model for MR was rs694-rs927650, followed by rs307247-rs464653-rs927650. Some haplotypes in the PTH gene presented statistical significance. Our results suggest that SNPs in PTH, VDR, CYP24A1 and CYP27B1 genes are associated with the presence of mandibular retrognathism.