title: HLA-DRB1*15021 is the predominant allele in Japanese patients with juvenile dermatomyositis.
abstract: OBJECTIVE
  To investigate HLA molecules and genes in Japanese patients with juvenile dermatomyositis (JDM).
  
  
  METHODS
  Twelve patients (8 girls and 4 boys) with ages of onset between 3 and 15 years were included. HLA class I antigen phenotypes were serologically typed by the Terasaki-NIH standard method. DNA was extracted from peripheral blood leukocytes using the phenol-chloroform extraction procedure, and stored at -70 degrees C until use. Genomic DNA for HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles in JDM patients and controls was determined by the direct sequence method.
  
  
  RESULTS
  HLA-A24 and B52 were each detected in 7 cases (OR = 0.86, 5.02, p = 0.930, 0.006, respectively). HLA-DRB1*15021 was observed in 7 patients. This was significantly more frequent than occurred in the controls (OR = 5.72, p = 0.002). Seven patients out of 12 (58%) had the combination HLA-B52, DRB1*15021, DQA1*0103, and DQB1*0601.
  
  
  CONCLUSIONS
  Our results suggest that the susceptibility gene for JDM either is HLA-DRB1*15021 or is present near the HLA-DRB1 locus. This differs from previous reports that describe the association with HLA-DQA1*0501 in Caucasian patients with JDM. The combination HLA-B52, DRB1*15021, DQA1*0103, and DQB1*0601 may contribute to the pathogenesis of JDM in Japanese patients.
authors.affiliation: Division of Immunology and Rheumatology, Department of Pediatrics, Yokohama City University School of Medicine, Yokohama, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Tomono
authors.forename: Masaaki
authors.initials: M
authors.lastname: Mori
authors.forename: Shoko
authors.initials: S
authors.lastname: Nakajima
authors.forename: Takako
authors.initials: T
authors.lastname: Miyamae
authors.forename: Shuichi
authors.initials: S
authors.lastname: Ito
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Mitsuda
authors.forename: Shumpei
authors.initials: S
authors.lastname: Yokota
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003882:Dermatomyositis / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D007564:Japan; D008297:Male
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains