Primary Sjogren's Syndrome Susceptibility Gene And Preeclampsia Candidate Genes

Part1 Whole exome sequencing to identifying susceptibility genes of pSSBackground:Sjogren’s syndrome is a common autoimmune disease characterized by lymphocytic infiltration of exocrine especially lacrimal and salivary glands results the dysfunction of the glands.Besides dry mouth(xerostomia)and dry eyes(keratoconjunctivitis sicca),SS can also present as a systemic disease.Sjogren’s syndrome may occur alone defined as primary Sjogren’s syndrome or in association with another autoimmune disease named secondary Sjogren’s syndrome.pSS is the second most common systemic autoimmune disease after rheumatoid arthritis(RA).To date,the pathogenesis of pSS are unknown clearly which involves in both genetic and environmental risk factors.As one of research hotspots,genetic studys of pSS have relied mostly on candidate gene approaches.In recent years,there are two Genome wide association studies launched in Caucasian and Chinese populations respectively and identified new variants associated with pSS.Objective:Previous studies identified numerous variants which locate in introns or intergenic regions.However,most of these variants are less functional.Our research aims to identify functional variants in exons which may associate with pSS in Chinese Han population.Methods:The basic information as well as peripheral blood samples of 91 pSS patients and 152 healthy controls were collected.Then the DNA were extracted and stored for use.11 patients affected by pSS and 6 unaffected individuals were subject to WES by Ion Proton sequencing system.The alignment and variant call as well as other basic processes were operated through TS systerm.Subsequently,the bioinformatic annotation was achieved by IR workflow.The annotation information includes gene name,chromosomal location,amino acid changes,GO annotation,allele frequency and SIFT,Polyphen predicted results and so on.Candidate variants which may associate with pSS were selected according to these information.Results:1.171 genes were selected as pSS candidate genes through NCBI-Gene database and the variants in these genes were selected from our WES data.Then 5 polymorphic sites,including ETS1 c.*3297G>A,DARC c.205C>T,DARC c.131G>A,KIR2DL1 g.55295367G>A and KIR2DL3 c.686C>T,were genotyped using sanger sequencing in 80 sporadic cases and 146 controls after validation of their WES results.The analysis results showed that there were no significant difference in allele frequency and genotype distribution of these sites between the two groups(P>0.05).2..We also selected 25 rare variants(MAF<0.01)which were not found in the 6 controls.Gene IFIH1,CREBBP,OAS1 were enriched in Influenza A,Herpes simplex infection and Hepatitis B pathways through function enrichment analysis.Conclusions:1.ETS1 c.*3297G>A,DARC c.205C>T,DARC c.131G>A,KIR2DL1 g.55295367G>A and KIR2DL3 c.686C>T may not associated with pSS in Chinese Han population.2.Rare exonic mutations may account for the susceptibility of pSS.IFIH1,CREBBP and OAS1 may be the susceptibility genes of pSS in Chinese Han population.However,they need to be validated in futher study.Part2 Candidate genes association study of preeclampsia in Chinese Han womenObject:Preeclampsia(PE),characterized by de novo hypertension and proteinuria in the mother which occurs after 20 weeks of gestation,is one of the most common pregnancy complications.Many factors,including hereditary factors,immune maladaptation,placenta ischemia,vascular endothelial cell dysfunction,and oxidative stress,contribute to the complex etiology and pathogenesis of PE.We performed an association study between fifteen SNPs and preeclampsia in Han Chnese women,in order to find the genes or SNPs associated with PE.These fifteen SNPs include rs12711941,rs7576192,rs7579169 which locate in 2q14.1 near the gene INHBB,rs2507800 in ANG-1,rs4880 in SOD2,rs1799895 in SOD3 and 9 tagSNPs in TIMP3 gene.Methods:Genomic DNA were extracted from all the participants including 181 PE patients and 203 healthy pregnant women.The fifteen SNPs were genotyped using the Sequenom method.and the association between these SNPs with PE were analysed by SPSS12.0.Results:The allele frequency of rs7579169 was different between PE patients and healthy controls(P=0.02,OR=1.44,95%CI 1.05-1.98)and significantly difference was also observed in dominant model(P=0.040,OR=2.278).The allele frequency and genotppe distribution of rs7576192 and rs12711942 were not different between PE patients and controls(P=0.12,P=0.37).Then the analyzation of the two SNPs in three models showed no difference as well.However,in haplotype analysis,the GGC and GGT haplotype of rs12711941,rs7576192 and rs7579169 showed difference between PE group and controls(P=0.030,P=0.046).There were no significant differences in allele frequency and genotypic distribution of rs2507800,rs4880 and rs1799895 between PE patients and healthy controls.Significant differences were not observed in both dominant and recessive models of rs2507800 and rs4880.In gene TIMP3,the genotype distribution of rs135025 was shown to differ between the multigravidity PE subgroup(>3)and controls under additive(P=0.018)and recessive models(P=0.008),while the genotype distribution of rs80272 differed significantly between the severe PE subgroup and controls under additive(P=0.014)and dominant models(P=0.041).In haplotype analysis,the ACGTAAGCG haplotype(rs135025,rs135029,rs137487,rs241890,rs242078,rs5754312,rs715572,rs80272 and rs9609643)showed difference between PE group and controls(P=0.030,P=0.046).Conclusions:In our study,rs7579169 but not rs7576192 and rsl27119415 might associate with PE and in haplotype analysis,the GGC and GGT haplotype of rs12711941,rs7576192 and rs7579169 showed association with PE.Though none of the 9 tagSNPs were associated with PE,the ACGTAAGCG haplotype was found to contribute the risk of PE.The SNPs rs2507800,rs4880 and rs1799895 in genes ANG-1,SOD2 and SOD3 were not associated of PE in Chinese Han women.