Polymorphism in 4'-UTR Region of PITX2 in Vertical Mandibular Symmetry

Study on specific genetic pathways of condylar phenotype variation related to vertical mandibular asymmetry remain rare. PITX2, a gene active in the Nodal Pathway that determines the left-right symmetry during embryogenesis, has been reported in expression and regulation of skeletal-muscle development as well as differentiation of satellite cells in adult muscle. The aim of this study is to analyze the phenotypes of expressed PITX2 and its polymorphisms in vertical mandibular asymmetry based on skeletal and dental analysis. Pre-treatment panoramic radiographs from selected 62 orthodontics patients (20.7 ± 3.2 year old) were analyzed using Kjellberg symmetry Index. Subdivision of malocclusions that are limited to Angle’s classification was recorded. DNA material was obtained using buccal swabs, followed by Polymerase Chain Reaction (PCR) and Sanger sequencing with ChromasPro 2.13 software (Technelysium, Queensland, Australia) and then compared to archival data from gene bank number ENSG00000164093 (www.ensembl.org).Genotype analysis showed 3 polymorphisms (rs72554076, rs761511445, rs372257787) in 4'-UTR of 16 subjects (25.8%) with various vertical mandibular asymmetry causing a C>A change at 47-105 in 13 patients, G>A change at 47-9 in 1 patient and G>T change at 46+100 in 2 patients, respectively. The characteristics of vertical mandibular asymmetry and canine subdivision dominated in these subjects. Our findings suggest that complex polygenic trait of vertical mandibular asym metry should consider PITX2 polymorphisms that related to muscular disorder.