Genetic predisposition to a skeletal class II malocclusion in a Southern Chinese population

Abstract

AIM: To identify the genetic predisposing factors of skeletal Class II malocclusions in a southern Chinese population. SUBJECTS AND METHOD: Southern Chinese volunteers, including 198 normal sagittal skeletal subjects and 162 skeletal Class II patients, were recruited for this case-control association study. Genomic DNA was isolated from whole blood. Fiftyeight single nucleotide polymorphisms (SNPs) from eight genes, which participate in the process of mesenchymal stem cell proliferation and chondrogenesis in the mandibular condyle, were genotyped using the Sequenom platform. Association testing was performed by chi-square test. The Hardy-Weinberg equilibrium test and linkage disequilibrium test were executed with Haploview software. RESULTS: The increased susceptibility to a skeletal Class II malocclusion was found to be associated with one SNP in gene NOS3, rs3918188 (OR = 2.337 with 95% CI = 1.192-4.582 for AA, compared with CA and CC genotypes). Allele A in rs3918188 (P = 0.019, OR = 1.449 with 95% CI = 1.062-1.976) was signifi cantly associated with the trait. CONCLUSIONS: SNP rs3918188 is one predisposing factors for a skeletal Class II malocclusion in a southern Chinese population. Further studies on genetic markers may expand understanding of the genetic control in craniofacial morphological determinants and help in the prediction of craniofacial growth.