A Preliminary Study On The Association Between Myosin 1H Gene Polymorphism And Skeletal Mandibular Retrusion

Objective:At present,there are few studies on the effect of myosin I(MYO1H)gene mutation on skeletal mandibular retrusion.There is no report on the related research of the Han population in Taiyuan,Shanxi Province in China.Therefore,the purpose of this study was to analyze the relationship between the single nucleotide polymorphism of the rs3825393locus of type I myosin gene and susceptibility of Han people with skeletal mandibular retrusion in Taiyuan,Shanxi Province.Methods:Including 40 patients with skeletal Class II malocclusion,the main feature of mandibular retrusion from Taiyuan,Shanxi Province,who were admitted to the Orthodontic Department of the First Hospital of Shanxi Medical University from February 2016 to January 2017 as the case group.as the case group,including 22 males and 18 females,Age 12 to 29 years old;the control group consisted of 40 patients with skeletal class I,including 26 males and 14 females,aged 13~28 years.After informed consent from patients and their families,peripheral venous blood was collected and exon30 of MYO1H gene was amplified by PCR.PCR-RFLP was used to detect the polymorphism of MYO1H gene rs3825393;Using Pearson X~2 to test whether the genotypic distribution of the case group and the control group is consistent with the Hardy-Weinberg equilibrium law;Comparing cephalometric measurements and baseline data between the two groups;Logistic regression was used to analyze the relationship between MYO1H gene polymorphism and age,sex and MR susceptibility;A case-control analysis method was used to compare the genotype and allele frequencies in the case and control groups and to explore the relationship between them and the mandibular retrusion phenotype.Results:1.The genotypes of the case group and the control group are in accordance with the Hardy-Weinberg equilibrium law,which proves that the selected samples of the two groups have a representative group.2.There was no significant difference in gender and age between the case group and the control group(P>0.05).There were significant differences between the two groups in the cephalometric SNB angle,ANB angle,and Z angle(P<0.05).The rest of the measured values were not divergent,demonstrating that the included MR patients and normal controls were eligible for diagnosis and inclusion criteria.The samples were representative.3.Logistic regression analysis was used to analyze the relationship between age,sex and MYO1H polymorphism and MR susceptibility.The results showed that the whole regression model was statistically significant,proving that MR was correlated with genotype of MYO1H(P<0.05);age and gender no correlation(P>0.05).4.Significant difference in genotype distribution between the case group and the control group(P=0.014).All samples were digested by the restriction endonuclease Sau96I and35 GG genotypes were obtained:24 cases in the control group.There were 11 cases in the case group and 37 AG genotypes:13 in the control group and 24 in the case group.There were 8 AA genotypes:3 in the control group and 5 in the case group.In the control group,the GG genotype accounted for the most,60%,while the AG genotype was significantly higher in the case group than the other two types,accounting for 60%.The proportion of mandibular retrusion in the Han population in Taiyuan,Shanxi Province,which represents the AG genotype,has increased.5.G allele and A allele have significant differences in distribution between the two groups(P=0.012).The carrying frequency of allele A in the case group was significantly higher than that of the control group.It was proved that the Han population in Taiyuan,Shanxi Province carrying the AG and AA genotypes increased the risk of mandibular retrusion.Conclusion:This study found that the polymorphism of rs3825393 in the MYO1H gene may be a risk factor for skeletal mandibular retrusion in the Han population in Taiyuan,Shanxi.