title: Interleukin-21 receptor gene polymorphisms in kawasaki disease.
abstract: OBJECTIVE
  Interleukin-21 receptor (IL-21R) gene polymorphism is related with the development of systemic vasculitis. In this study, we investigated the polymorphisms of IL-21R gene in patients with Kawasaki disease (KD).
  
  
  METHODS
  We genotyped the promoter region of IL-21R gene (-2500 bp to +1 bp) in 100 patients with KD and 100 healthy controls. All study subjects were Korean. We designed five pairs of primers and performed polymerase chain reaction (PCR) and direct sequencing. We analyzed whole promoter sequences of 200 individuals with comparison to reference sequences of IL-21R gene (NG_012222.1/NC_000016.9).
  
  
  RESULTS
  We found five single nucleotide polymorphisms (SNPs) of which minor allele frequency (MAF) >0.01 in the promoter region of IL-21R gene. Those are -1681 G>T (chromosome site 27411802), -379 G>A (27413104), -332 G>C (27413151, rs2214537), -237 A>T (27413246), and -53 G>A (27413430). There is no significant difference in MAF of each SNP between patients with KD and healthy controls except -237 A>T. Twenty five patients with KD had more than 1 SNP in contrast to only seven healthy controls had. The patients with KD have significantly more IL-21R gene polymorphisms than controls (odds ratio: 3.0, 95% confidence interval: 1.6-5.6, p=0.0005). There was no significant correlation between IL-21R gene polymorphisms and the serum level of IL-21. The serum level of total IgE was not significantly correlated with the presence of IL-21R gene polymorphisms.
  
  
  CONCLUSIONS
  Our data suggest that the genetic susceptibility profile for KD may include IL-21R gene.
authors: Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Korea.
authors: Mi Hyun
authors: MH
authors: Kim
authors: Yon Jung
authors: YJ
authors: Bae
authors: Hyun Keun
authors: HK
authors: Lee
authors: Yeong Ro
authors: YR
authors: Lee
authors: Dong Hoon
authors: DH
authors: Lee
authors: Kiho
authors: K
authors: Bae
authors: Sang Baek
authors: SB
authors: Koh
authors: Mee Kyung
authors: MK
authors: Namgoong
authors: Byung Ho
authors: BH
authors: Cha
authors: Hae Yong
authors: HY
authors: Lee
keywords: Mucocutaneous lymph node syndrome; Polymorphism, genetic; Receptor, Interleukin-21