Association between myosin 1H polymorphisms and skeletal-facial profile in Taiwanese patients with mandibular prognathism.

BACKGROUND/PURPOSE: Mandibular prognathism (MP; skeletal Class III malocclusion) results from complex genetic and environmental interactions. However, genetic variants related to craniofacial morphology in Taiwanese individuals remain underexplored. This study examined the association between single nucleotide polymorphisms (SNPs) in the myosin 1H (MYO1H) gene and cephalometric parameters of MP in a Taiwanese population. MATERIALS AND METHODS: Blood samples and lateral cephalograms were collected from 185 Taiwanese participants. Based on the ANB angle, subjects were classified into an Class III group (ANB <0°) and a NON-Class III group (ANB ≥0°). MYO1H SNPs (rs3825393, rs7319591, rs10850110) were genotyped using quantitative real-time polymerase chain reaction. Associations between genotype distributions and skeletal classification were analyzed using Pearson's chi-square test. RESULTS: The MYO1H rs10850110(G > A) polymorphism was significantly associated with MP. Individuals with the GA genotype showed a lower risk of MP than those with the GG genotype (odds ratio [OR] 0.43, P = 0.01). Under dominant and recessive models, the GA + AA group had approximately a 50 % lower risk than the GG group (OR = 0.50, P = 0.04). Cephalometric data indicated that GG carriers exhibited significantly larger SNB angles and more negative ANB and Wits appraisal values compared with GA carriers. CONCLUSION: The MYO1H rs10850110(G > A) polymorphism is significantly associated with MP in Taiwanese individuals, with the GA genotype showing a protective effect. These findings support the role of MYO1H in mandibular growth regulation and suggest potential population-specific genetic variation.