A Case Control Study On The Association Between DLX1 And DLX2 Gene Polymorphism And Dental Fluorosis Caused By Coal-burning Pollution

Objective: This study aims to observe the distribution of rs788172 locus and rs788173 locus of DLX1 gene and rs743605 locus and rs3762499 locus of DLX2 gene in patients with dental fluorosis caused by coal-burning pollution and healthy people in Guizhou Province.The study also investigates the relationship between dental fluorosis and genetic susceptibility or tolerance by analyzing DLX1 and DLX2 gene polymorphism.Methods: This case-control study included 117 dental fluorosis patients in the case group and 109 non-dental fluorosis subjects in the control group in Bijie city.Subjects in each group ranged in age from 18 to 84.The remaining peripheral blood samples in all subjects were collected after routine blood test.We collected genomic DNA from blood samples,screened the SNP locus for PCR amplification,used Sanger sequencing technology to detect the genotypes of single nucleotide polymorphism loci,and analyzed the differences in genotypes and allele frequency distribution among groups.Results: 1.The genotype distribution of each target locus in this study followed the Hardy-Weinberg equilibrium(P >0.05).2.There were no significant differences in genotype and allele frequency distribution of rs788172 locus and rs788173 locus between the case group and the control group(P >0.05).There were also no significant differences in genotype and allele frequency distribution among mild,moderate and severe dental fluorosis(P >0.05).3.There were no significant differences in genotype and allele frequency distribution of rs743605 locus between the case group and the control group(P >0.05).Among the mild,moderate and severe dental fluorosis,the frequency of CC genotype in severe dental fluorosis was significantly higher than that in mild and moderate dental fluorosis.The frequency of T allele in severe dental fluorosis was significantly lower than that in mild and moderate dental fluorosis,with statistical significance(P<0.05).4.The distribution of genotype and allele frequency of rs3762499 was significantly different between the case group and the control group(P<0.05).The AG genotype frequency in the control group was significantly higher than that in the case group,and the AG genotype had a lower risk of dental fluorosis compared with the AA genotype(OR=0.345).There were no significant differences in genotype and allele frequency distribution among the mild,moderate and severe dental fluorosis(P >0.05).Conclusion: 1.There was no significant correlation between rs788172 and rs788173 polymorphisms in DLX1 gene and dental fluorosis caused by coal-burning pollution.2.The polymorphisms of rs743605 and rs3762499 in DLX2 gene were correlating with dental fluorosis caused by coal burning pollution.Among them,statistical results of rs743605 locus suggested that in patients with dental fluorosis,individuals with the CC genotype had a higher risk of severe dental fluorosis.Statistical results of rs3762499 indicated that the AG genotype had a lower risk of dental fluorosis than the AA genotype under high fluoride exposure,and the AG genotype may be a protective factor.