Association Between Positive Missense Mutation Sitesin Genome-wide Association Studies And Asthma In Guangxi Zhuang Population Of China

Objectives To explore the association of five positive missense mutations in genome-wide association study of TLR1 gene rs4833095,GSDMA gene rs7212938,rs3894194,GSDMB gene rs2305480 and CDHR3 gene rs6967330with asthma in Guangxi Zhuang population,and to further research the genetic mechanism of asthma in Guangxi Zhuang population.Methods A case-control study was conducted.123 asthmatic patients in the case group and 100 healthy people in the control group were enrolled.Firstly,DNA was extracted from peripheral blood,and then five loci,rs4833095,rs7212938,rs3894194,rs2305480,and rs6967330,were selected through GWAS Catalog database.The primers of the five loci were designed by combining SNP database of NCBI and Primer 3 Online design.The product fragments were obtained by digesting DNA by multiple PCR-LDR,and then identified by sequencer to obtain genotype maps of 5 loci.SPSS 24.0 and SHEsis were used to analyze the basic characteristics of the subjects,Hardy-Weinberg equilibrium test,genotype frequency distribution difference,allele frequency distribution difference and the relationship between genetic model and asthma.Linkage disequilibrium analysis of rs3894194,rs7212938 and rs2305480 loci and haplotype construction of these three loci were carried out,and then the correlation between each haplotype and asthma was analyzed using Haploview4.2.Results 1.Basic characteristics of the experimental object:There was no significant difference in gender and weight between the two groups(P=0.091);there was significant difference in average age and height between the case group and the control group(P=0.000).2.Association analysis of five loci with asthma:(1)The frequency distribution of genotypes and alleles in the control group was in accordance with Hardy-Weinberg equilibrium(P>0.05).There were polymorphisms in five loci of TLR1 gene rs4833095,GSDMA gene rs7212938,rs3894194,GSDMB gene rs2305480 and CDHR3 gene rs6967330 in Guangxi Zhuang population.(2)There was no significant difference in the distribution of genotypes and allele frequencies of 5 loci between the case and the control groups.(3)Logistic regression analysis showed that allele model,homozygote model,heterozygote model,dominant model and recessive model of five loci had no significant relationship with asthma.3.Linkage disequilibrium and haplotype analysis among three loci:Linkage disequilibrium existed among rs3894194,rs7212938 and rs2305480 on 17q21(D'>0.8),among which there was a strong LD between rs2305480 and rs3894194,rs3894194 and rs7212938(r~2>0.33).Haploview 4.2 was used to construct haplotypes between three loci:Block 1:rs2305480 and rs3894194,block 2:rs2305480 to rs7212938,block 3:rs3894194and rs7212938.The distribution of CC haplotypes in the block 1 constructed from rs2305480 and rs3894194 loci was significantly different between the two groups,in the case group,the haploid distribution was more frequent(?~2=5.17,P=0.02,OR=1.72,95%CI=1.07-2.79).There was no significant difference in the distribution of haploid CT,TC and TT between the two groups(P>0.05).The distribution of haplotype CCT consisting of rs2305480,rs3894194 and rs7212938loci was significantly different between the case group and the control group(?~2=4.45,P=0.03,OR=1.74,95%CI=1.04-2.92).The other haploid CTG,TCT,CTT,CCG and TTG were not significantly different between the case group and the control group(P>0.05).There was no significant difference in the distribution of haploids in block 3 between the case group and the control group(P>0.05).Conclusion(1)There were polymorphisms in five loci of TLR1 gene rs4833095,GSDMA gene rs7212938,rs3894194,GSDMB gene rs2305480 and CDHR3 gene rs6967330 in Guangxi Zhuang asthmatic population.(2)There was no difference in genotype,allele distribution and genetic model analysis between normal Zhuang population and asthmatic patients in Guangxi.(3)The risk of asthma may be increased for individuals carrying the haplotype CC haplotype constructed by rs2305480 and rs3894194 loci and the haplotype CCT constructed by rs2305480,rs3894194 and rs7212938 loci in Guangxi Zhuang population.