Identification Of Susceptibility Genes In Kawasaki Disease Using Whole Exome Sequencing

Objective:It is the first time we use whole exome sequencing(WES) to explore the new susceptibility loci of Kawasaki disease(KD), and further study the relationship between the susceptibility loci and Coronary artery lesion(CAL).Methods:Firstly, DNA was extracted from peripheral blood of 6 children with recurrent KD hospitalized in Children’s Hospital of Soochow University and 6 healthy children.Secondly, we selected candidate susceptibility loci of Kawasaki disease through the whole exome high-throughput sequencing and bioinformatics data statistical analysis in the two groups. And then, the Polymerase chain reaction(PCR) and direct sequencing of the candidate susceptibility loci were performed to verify the accuracy of the exome sequencing. Lastly, we validated the candidate susceptibility loci in 50 KD patients and 49 healthy children and selected a significant difference in the genotype frequencies between the two groupsthat is to be the target susceptibility gene of KD. In order to further discuss the relationship between CAL and the target susceptibility gene, the 50 KD patients were divided into coronary artery lesion group(n=19) and no coronary artery lesion(NCAL)group(n=31). Then, in the two subgroups the differences about allele and genotype frequencies of the target susceptibility gene were compared.Results:We performed the whole exome sequencing, bioinformatics data statistical analysis and screened 12 SNPs of 5genes(SPEF2、EYS、SLC15A1、PTPN21、HLA-A) as the candidate susceptibility loci in KD. Then analysis and validation in expanded cases and control group, finally we identified the SLC15A1 SNPrs2274828 as the target susceptibility gene in KD.In the expanded KD cases group, the frequency of genotype CT and allele T of SLC15A1 SNPrs2274828 locus were significantly higher than that inhealthy control group( p <0.05). Analysis relationship between CAL and the SLC15A1SNPrs2274828 locus, we discovered the frequency of genotype CT and allele T of SLC15A1 SNPrs2274828 locus in KD children with CAL were significantly higher than that in KD children without CAL( p <0.05).Conclusion:We performed the whole exome sequencing in the recurrent KD group and healthy control group and identified the SLC15A1 gene as the susceptibility gene of KD.T allele of SLC15A1 gene SNP rs2274828 may be a risk factor of developing KD.T allele of SLC15A1 gene SNP rs2274828 is thought to increase risk of developing coronary artery lesion in children of KD.