Investigation Of The Difference On SNP Site Polymorphism Between Hantavirus Infected And Non-infected Of HLA-B,DQ Gene

Objective: According to the detection on the SNP sites in HLA-B and-DQ region of HFRS patients and healthy, analyze the genotype and allele frequencies, study the relationship between human infection with Hantavirus and genetic characteristics.Methods:1 To collect the whole blood samples of HFRS patients or suspected patients in Hebei province, through the epidemiological investigation; to collect the whole blood samples of healthy for control;2 To select HV IgM,IgG antibody-positive whole blood samples, by using HFRS virus antibody diagnostic kit (colloidal gold method);3 To extract the genomic DNA from positive and healthy whole blood samples;4 To search for SNP sites of HLA-B and-DQ from GENEBANK according to some documents, design allele-specific primers, amplify the SNP sites using allele-specific primer polymerase chain reaction (ASP-PCR) and do electrophoresis and observation;5 To genotype the SNPs and analyze the characteristics of gene polymor-phism, the associations between the single nucleotide polymorphisms and human hantavirus infection were investigated through case-control study.Results:1 In 2009, 221 cases of HFRS were reported in Hebei province, a significant decrease compared with previous years; the incidence was 0.032/million. The HFRS was widespread in all of the 11 districts of Hebei province , the high incidence districts concentrated in Qinhuangdao and Shijiazhuang, taking up 49.77% of all cases; the following ones were Cangzhou, Tangshan, Baoding, Xingtai and Zhangjiakou; Chengde, Hengshui, Handan, Langfang were the lower ones.2 The HFRS room of the Hebei Province center for disease control and prevention (total) collected 85 blood samples in total of HFRS patients and suspected patients, and test positive for 36 (including 24 whole blood positive samples) through the HFRS antibody diagnostic kit (colloidal gold method), the positive rate was 42.35%.3 According to Hardy-Weinberg equilibrium test formula, calculate the theoretical number by the actual number of each genotype experiment with the SNP sites, statistical results showed that: (1) rs41557013 siteχ2=2.357, P=0.308>0.05; (2) rs34933313 siteχ2=3.297, P=0.192>0.05; (3) rs71543422 siteχ2=1.752, P=0.416>0.05; (4) rs12722040 siteχ2=1.067, P=0.587>0.05; (5) rs1142324 siteχ2=0.036, P=0.982>0.05. It prompted that the actual genotype frequencies and the theoretical genotype frequencies were not statistically significant in each SNP site. The distribution of allele and genotype of the site was accordance with Hardy-Weinberg's Law of Equilibrium and exhibited the representative of population.4 Comparison between genotype frequencies and the allele genotype frequencies in each SNP site , the results showed: the frequencies of CC genotype of rs34933313 site in patient group and control group were 4.17% and 29.41% respectively, the frequencies of GG genotype were 12.50% and 15.69% respectively, the frequencies of CG genotype were 83.33% and 54.90% respectively. The frequencies of CC and GG genotype in patient group were lower than control group, The frequency of CG genotype in patient group was significantly higher than those in control group (χ2=7.050, P=0.029<0.05),with significant difference. It prompted that the genotype of rs34933313 site might be associated with HV infection, and CG genotype might increase the risk of human infected. The frequencies of C allele were 45.83% and 56.86% in patient group and control group respectively. The frequencies of G allele were 54.17% and 43.14% in patient group and control group respectively. There was no statistically significant with the frequencies of C allele and G allele between patient group and control group (χ2=1.595, P=0.207>0.05). The other four SNP sites (rs41557013, rs71543422, rs12722040, rs1142324) of genotype frequencies and the allele genotype frequencies between patient group and control group were not statistically significant.Conclusion:1 The gene polymorphism of rs34933313 site may be associated with people HV infection, CG genotype may increase the risk of human infection with HV.2 There is no correlation between the gene polymorphism of rs41557013, rs71543422, rs1272204, rs1142324 sites and the HV infection in human.3 HLA-B gene is probably associated with the human infected with HV.