A Preliminary Study On The Difference Of Dental Caries-related Gene Polymorphisms Between Baiku Yao And Zhuang Populations In Guangxi

Objective:To analyze gene polymorphisms of 41 loci in 23 dental caries related candidate genes in Baikuyao and Zhuang population from the same region,and to find out the distribution of differences in alleles and genotypes between Baikuyao and Zhuang population,therefore finally understand the relationship between differential gene polymorphisms and the low caries prevalence of Baikuyao population.Methods:1.Epidemiological survey Total 59 subjects aged 12 years old and over were randomly selected from Lihu Yao village in Nandan County,Guangxi.Baikuyao subjects were 35 and Zhuang were 24 among sample.Data were collected through oral health examinations and questionnaire surveys.Oral health examination mainly dental caries was performed among sample study group.Questionnaire was conducted by a face-to-face interview.The information of questionnaire included sociodemographic data,dietary conditions and oral related behaviors of the subjects;Venous blood samples were collected and stored in EDTA disposable anticoagulant tubes.2.Laboratory testingLaboratory testing mainly included the extraction of genomic DNA and the detection of SNP genotypes related to the candidate genes.The genomic DNA of the blood sample was extracted using the kit method.Sequenom Mass ARRAY(?)SNP molecular weight array technology was used to detect Single Nucleotide Polymorphisms in the caries-related candidate genes.The detection process was combined with multiplex PCR,Mass ARRAY i PLEX single-base extension and matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry/mass spectrometry(MALDI-TOF)for typing detection.3.Statistical analysisThe database was built by Epidata3.1 database management software and was sorted out by Excel2007 software.After logical verification,data was analyzed by SPSS22.0 and Plink statistical analysis software package.Rate(%),composition ratio(%),mean and standard deviation was calculated.Chi Square test and t test were used to test the difference between groups at test level α=0.05,P<0.05;The Hardy-Weinberg’s equilibrium test was performed for Test of Goodness of Fit at the level α= 0.05,P> 0.05.Single factor analysis and logistic regression analysis was used for correlation analysis.Results:1.The caries prevalence、DMFT and DMFS of Baikuyao population were lower than that of Zhuang population in the same region(P<0.05)2.The result from Hardy-Weinberg balance test showed that the genotype distribution of the gene loci in Baikuyao and Zhuang population was well-balanced and was in a state of equilibrium(P>0.05).3.Difference distribution of caries related gene polymorphism(Alleles,genotypes)existed between Baikuyao and Zhuang population.3.1 The Distribution frequency of alleles of MPPED2 gene,loci rs11031093,rs7121800;TUFT1 gene,loci rs2337359,rs3748608,rs3748609,rs7554707;DEFB1 gene rs11362;ENAM gene,rs12640848 locus;CCNB1 gene rs875459,locus and GLUT2 gene locus rs1499821 in Baikuyao and Zhuang population of the same area were different(P<0.05).There was significant difference in genotype frequency distribution between two groups(P<0.05)in the MPPED2 gene rs11031093,rs7121800;TUFT1 gene rs3748608,rs2337359,rs3748609,rs7554707;rs12640848 locus of the ENAM gene;rs10489788 locus of the EDARADD gene and the rs875459 locus of the CCNB1 gene.3.2 Among the caries group,the distribution of alleles in the MPPED2 gene rs11031093 locus;the TUFT1 gene rs3748608,rs3748609,rs7554707,rs2337359;DEFB1 gene rs11362 locus;CCNB1 gene rs875459 locus and rs12640848 locus of ENAM gene were found different between Baikuyao and Zhuang population.The difference was statistically different(P<0.05).There was significant difference in genotype distribution of gene loci between the two populations(P<0.05)in the MPPED2 gene rs11031093,rs7121800 loci,TUFT1 gene rs3748608,rs3748609,rs7554707 loci and rs12640848 locus of ENAM gene.3.3 Among non-caries group,the distribution of alleles in the ENAM gene rs12640848 locus and the TUFT1 gene rs3748609,rs7554707 and rs3748608 loci and TAS1R2 gene rs4912075,FZD1 gene rs288830 among of Baikuyao and Zhuang population was different(P<0.05).And there was significant difference in genotype distribution of gene locus between two groups(P<0.05)in the TUFT1 gene rs2337359,rs3748609,rs7554707 loci and FZD1 gene rs288830 locus.4.Single factor analysis of the relationship between caries related gene polymorphism and caries in Baikuyao and Zhuang populations.4.1 The frequency of allele G of TUFT1 gene rs3748609 and rs7554707 in non-caries group was higher than that in caries group in Baikuyao population(OR=0.0.118,P=0.000).The genotype TT of TUFT1 gene rs2337359 in Baikuyao population was more frequently distributed in non-caries group(46.2%)than in caries group(4.5%)(P<0.05).4.2 Related to the allele distribution in Zhuang population,the frequency of the allele A of the rs12640848 of the ENAM gene was lower in no caries group than in caries group.However,the difference was no statistically significant(OR=3.286,P=0.296).The frequency of the genotype AG of FZD1 gene rs288830 was lower in the nocaries group(0.0%)than in caries group(72.8%)(P<0.05).5.The relationship between gene polymorphism and caries in unadjusted and adjusted models.The frequency of allele G in the TUFT1 gene rs3748609 and rs7554707 was higher in non-caries group than in caries group.There was no significant difference in the non-adjusted model(OR=0.386,P=0.076),but there was significant difference in the adjusted model(OR=0.174,P=0.018)after adjusted for age and sex in undjusted model.Conclusions:1.There are differences in the single nucleotide polymorphisms of loci of MPPED2 gene,TUFT1 gene,DEFB1 gene,ENAM gene,CCNB1 gene,GLUT2 gene EDARADD gene TAS1R2 gene and FZD1 gene between Baikuyao and Zhuang populations.2.Single factor analysis found that the frequency of allele G in the TUFT1 gene rs3748609 and rs7554707 was higher in the Baikuyao non-caries group than in the caries group.This suggests that allele G of TUFT1 gene rs3748609 and rs7554707 may be a protective allele for Baikuyao population.The allele A of ENAM gene rs12640848 was less frequently distributed in the Zhuang nationality non-caries group than in the caries group,suggesting that the allele A of ENAM gene rs12640848 may be a susceptible gene for for caries in Zhuang population.3.The frequency of allele G in the TUFT1 gene rs3748609 and rs7554707 was higher in non-caries group than in caries group.This suggests that allele G of TUFT1 gene rs3748609 and rs7554707 may be a protective allele for caries in Baikuyao population.These results still need to be confirm in more study with large samples.