Identifying Susceptibility Genes Of Childhood Bronchial Asthma Within 5q31-33 By Exome Sequencing Technology

Objective: To identfy susceptibility genes of childhood bronchial asthma within5q31-33 by whole exome sequencing technology.Methods: 18 complete trios of bronchial asthma composed of a patients and their biological parents participated were collected from the first affiliated hospital of Wannan Medical College and other hospitals.One of the 18 complete trios in which mother and son are patients with asthma and father is normal was selected to whole exome sequencing.In addition,we choose 20 severe patients with asthma from the 120 sporadic cases and explore the SNPs associated with asthma in the 5q31-33 region by whole exome sequencing.Results: 1.We choose a trios in which mother and son are patients with asthma and father is normal to whole exome sequencing and analysis the sequencing results by multiple steps.Finally,we identified a missense mutation p.Ala514 Thr which mother and son have together but not in father,the mutation located in the PCDH 1 gene exon 2region.2.A total of 124 mutations that have statistically significant difference between the 20 cases with severe asthma and 20 cases of healthy control were detected in this study by analyzing the results of whole exome sequencing in the 5q31-33 area(P<0.05).Conclusion: 1.PCDH1 could be one of the susceptible genes of bronchial asthma.2.Whole exome sequencing is one of the effective methods to explore the susceptibility genes for complex diseases,especially for rare mutations.Compared with other methods,it has many advantages,such as fewer samples,higher throughout,lower cost and so on.Objective: To identify the polymorphism of promoter and coding region of PCDH 1gene by Sanger sequencing.Methods: Randomly collected 150 cases of healthy children and 138 cases of bronchial asthma patients as the research subjects.Identifying the polymorphisms in PCDH1 promoter and all exons region from the 288 subjects by using the PCR amplification and direct sequenceing technology.The sequencing results were compared with the Hap Map and NCBI database to determinate the PCDH1 ploymorphisms characteristic.The genotype and allele frequency for each locus were compared between the asthma group and control group by Pearson ?2 test.Results: 1.A total of 5 polymorphisms loci were detected in PCDH1 gene region and 4of them were newly discovered.2.No statistically significant difference were found for the genotype and allele frequency of each locus between the 138 cases of asthma patients and 150 cases of heathy children(P>0.05).Conclusion: No polymorphisms loci associated with asthma were detected in the PCDH1 gene in this study.However,because of the small sample size and the possible population factors,further verification is needed.