Parathyroid Hormone Gene and Genes Involved in the Maintenance of Vitamin D Levels Association with Mandibular Retrognathism.

Erika Küchler,Caio Reis,Peter Proff,Christian Kirschneck,Paulo Nelson-Filho,Mírian Matsumoto,Maria Oliveira,Guido Marañón-Vásquez,Maria Stuani

doi:10.3390/jpm11050369

Abstract

In this study we evaluated whether single nucleotide polymorphisms (SNPs) in the genes encoding PTH, VDR, CYP24A1, and CYP27B1 were associated with mandibular retrognathism (MR). Samples from biologically-unrelated Brazilian patients receiving orthodontic treatment were included in this study. Pre-orthodontic lateral cephalograms were used to determine the phenotype. Patients with a retrognathic mandible were selected as cases and those with an orthognathic mandible 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 (22 males and 26 females) MR and 43 (17 males and 26 females) controls were included. The linear mandibular and the angular measurements were statistically different between MR and controls (p < 0.05). In the genotype and allele distribution analysis, the SNPs rs694, rs307247, and rs464653 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.

Highlights

Skeletal malocclusions are a set of human craniofacial morphologic characteristics that result in an improper skeletal relationship of the jaws and specific facial patterns
In the present study, we evaluated if single nucleotide polymorphisms (SNPs) in genes encoding parathyroid hormone (PTH), vitamin D receptor (VDR), CYP24A1, and CYP27B1 as well as the interplay among them were associated with Mandibular retrognathism (MR)
Most studies on the genetic background of skeletal malocclusion have focused on prognathism and Class III malocclusion, which is less frequent in the general population

Summary

Introduction

Skeletal malocclusions are a set of human craniofacial morphologic characteristics that result in an improper skeletal relationship of the jaws and specific facial patterns. A clinical and cephalometric study evaluating 114 patients (48 twin pairs and six sets of triplets) performed an intra- and inter-pair comparison to determine concordance/discordance rates for monozygotic and dizygotic twins. Many studies in different populations have been performed and demonstrated that genes involved in a variety of functions are associated with skeletal malocclusions and morphological patterns of the face [5,6]. Mandibular retrognathism (MR) is a common skeletal malocclusion in humans It refers to a retruded position of the mandible as a consequence of an anomaly of the skeletal jaw–cranial base relationship. This unfavorable positional relationship of developing jaws is diagnosed through image exams [7]

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