Objective: To study the frequency distribution of single nucleotide polymorphisms (SNPs) in two genes associated with incomplete Kawasaki disease (KD) (rs1569723 in CD40 gene and rs2736340 in BLK gene), and to investigate its association with the genetic susceptibility and clinical phenotypes of incomplete KD.
Methods: A total of 184 children with incomplete KD and 203 normal children were recruited to carry out a case-control study. The genotypes of SNPs in CD40 gene and BLK gene were determined using polymerase chain reaction-restriction fragment length polymorphism. The frequency distribution of genotypes was compared between the KD and control groups. The association between gene polymorphisms and clinical features of incomplete KD was analyzed.
Results: There were no significant differences in genotype (AA, AC, CC) and allele frequencies in CD40 SNP rs1569723 between the KD and control groups. There were significant differences in the frequency distribution of three genotypes (TT, CT, CC) in BLK SNP rs2736340 between the KD and control groups (P=0.031), and the KD group had a significantly higher frequency of T allele than the control group (P=0.007). There were significant differences in the incidence of conjunctival hyperaemia among the patients with different genotypes (rs1569723 in CD40 gene) (P=0.036). The SNP rs2736340 in BLK gene was associated with the extremity changes in KD patients (P=0.017).
Conclusions: The SNP rs2736340 in BLK gene is associated with the susceptibility to incomplete KD, and the SNP rs1569723 in CD40 gene and SNP rs2736340 in BLK gene are associated with some of clinical phenotypes of incomplete KD.